This is an exploratory editor's draft. RDF/HTML 0.1 is a proposal, not an established standard. Its data model, ordering profile, and vocabulary may change as IA² tests them against real documents.

RDF/HTML represents a parsed HTML document as RDF 1.2. Document, element, text, comment, document-type, and attribute nodes retain RDF identity, while RDF Collections or parent-scoped ordering relationships preserve children and mixed content. A dated generated vocabulary supplies current HTML element classes without making context-dependent classifications unconditional.

Introduction

HTML is normally authored as markup and then parsed into a DOM. RDF/HTML supplies the complementary direction: an RDF dataset describes the DOM nodes and their relationships, and a processor can materialize the corresponding document without treating an HTML string as the source of truth.

Motivation

Some systems already hold document structure as graph data: generated reports, knowledge-graph views, provenance-aware publishing pipelines, and independently contributed interface fragments. RDF/HTML lets those systems keep stable identity and ordinary RDF annotations on individual DOM nodes instead of hiding the document in one opaque HTML literal. Named resources and flat ordering facts can be contributed separately; compact RDF Collections remain available when one producer knows the complete sequence.

Goals and non-goals

Version 0.1 aims for deterministic, local materialization of parsed HTML-namespace light DOM from a versioned RDF vocabulary. It preserves node identity, mixed content, attributes, and enough ordering to derive one concrete tree. It is not a replacement for ordinary HTML authoring, a byte-preserving HTML syntax model, a complete WHATWG validator, a script execution model, or a general representation of every DOM and namespace feature.

This complete graph describes a document containing an empty head, followed by a body with a heading and a paragraph. Turtle collection syntax gives each parent one complete, ordered sequence of children.

The graph describes a DOM, not source bytes. Attribute order, optional tag spelling, indentation, character-reference spelling, and other lexical choices are outside this model. RDF/HTML also does not replace HTML's authoring-conformance rules.

RDF/HTML is distinct from IA² HTML/RDF. RDF/HTML starts with RDF and describes HTML nodes. HTML/RDF starts with an HTML host and expresses RDF statements inside it. A renderer may combine the two, but that integration is not part of this core data model.

This specification defines three conformance classes:

Conformance is independent of RDF serialization. A processor MAY accept Turtle, TriG, JSON-LD, an RDF/JS dataset, or another representation, but its input to the processing model is an RDF 1.2 dataset. A conforming processor MUST implement the bounded normalization rules in this document and MUST NOT depend on retrieving the vocabulary, running a general OWL reasoner, or executing arbitrary SHACL rules.

Partial descriptions are useful for independently maintained facts, but they are not silently completed. A processor MUST report why a selected document is not renderable when its children, cardinalities, or ordering do not determine one parsed HTML document.

RDF data model

The RDF/HTML namespace is https://ia2.dev/spec/rdf-html#. A dataset MAY describe more than one document, but processing is performed for one selected rdfhtml:Document resource at a time.

Dataset merge semantics

Structural processing uses the union of the dataset's default and named graphs. Assertions having the same subject, predicate, and object are one normalized fact even when they occur in several graphs; all supporting quads are consumed together. Different objects remain different facts and can violate cardinality. Graph names do not alter DOM structure. Applications needing provenance for a structural assertion SHOULD describe that assertion using RDF 1.2 reification or triple terms rather than relying on graph placement alone.

Structural node types

RDF/HTML defines these concrete structural node kinds:

Every materialized node MUST have exactly one concrete structural type from that list. Entailed supertypes such as rdfhtml:Element, rdfhtml:NormalElement, and content-category classes do not count as additional concrete types. Other RDF types and statements MAY annotate the same resource and do not affect structural processing.

Documents and bases

Every rdfhtml:Document MUST have exactly one rdfhtml:base value, and that value MUST be an absolute IRI. It supplies the URL-resolution context for the materialized document. The document resource remains RDF identity and MUST NOT be treated as interchangeable with its base IRI.

A renderable document MUST also have a dcterms:conformsTo link to a dated RDF/HTML vocabulary artifact supported by the processor. For this draft that artifact is rdf-html-2026-07-18.ttl. A processor recognizes this IRI locally and MUST NOT retrieve it while rendering.

rdfhtml:base is the nominal document URL and resolution context; it is not a DOM node and does not imply a described base element. A string serialization therefore returns the base separately. A browsing projection MAY add a marked runtime base element to establish that context in an iframe or equivalent host, but that element is not part of the faithful tree.

A document MUST contain exactly one rdfhtml:Html child and at most one rdfhtml:DocumentType child. Its rdfhtml:Html element MUST contain exactly one rdfhtml:Head child and exactly one rdfhtml:Body child.

Elements

A generated element class determines an HTML-namespace element's local name and syntax kind. For example, rdfhtml:Textarea identifies a textarea element and an escapable raw-text syntax kind. The generated element-reference appendix defines every current conforming HTML element in the dated snapshot.

A rdfhtml:CustomElement MUST have exactly one rdfhtml:localName string satisfying the HTML autonomous-custom-element name requirements. RDF/HTML 0.1 records the foreign syntax kind for provenance but does not define concrete MathML or SVG element classes. Such elements require an extension profile.

Void elements MUST NOT have children. The children of rdfhtml:Template describe the template element's template contents. Syntax kinds affect construction and serialization; content-category classes do not change the resulting DOM.

Text, comments, and document types

Every rdfhtml:Text and rdfhtml:Comment MUST have exactly one rdfhtml:data string and MUST NOT have children. Text nodes are ordered beside element nodes, so mixed content does not collapse into an aggregate textContent value.

A rdfhtml:DocumentType MUST have exactly one rdfhtml:documentTypeName string and MUST NOT have children. Version 0.1 does not model public or system identifiers.

Attributes

Every generated rdfhtml:AttributeDefinition is also an owl:DatatypeProperty whose rdfhtml:attributeLocalName determines the DOM local name. A known attribute SHOULD be asserted directly on its element. Its object MUST be one xsd:string literal without a language or base direction, containing the exact DOM content-attribute value. For example:

The empty string is the canonical direct value for a present boolean attribute. Generated value-syntax metadata is descriptive and does not coerce DOM strings into booleans, numbers, IRIs, or other RDF datatypes.

rdfhtml:attribute links an element to an rdfhtml:Attribute occurrence. This expanded form remains available when an occurrence needs RDF identity, provenance, or other annotations. Each occurrence MUST have exactly one rdfhtml:attributeValue string. A known occurrence MUST have exactly one rdfhtml:attributeDefinition link to its generated definition. It MAY also carry an explicit rdfhtml:attributeName, but that name MUST equal the definition's local name.

An occurrence without a generated definition MUST have exactly one rdfhtml:attributeName string. This generic form covers custom, future, data-*, ARIA, event-handler, and extension attributes. An optional rdfhtml:attributeNamespace absolute IRI records its namespace. An occurrence using a generated HTML definition MUST NOT carry an attribute namespace.

Before validation, a processor MUST normalize a direct generated property to the equivalent known attribute occurrence. Consistent direct and expanded assertions of the same expanded name and string value are harmless duplicates. Different values for the same expanded name are an error. Attribute ordering is not represented.

Definition resource names use a same-letter reflected Web IDL name when the Living Standard provides one, such as accesskey to rdfhtml:accessKey. Hyphenated names otherwise use mechanical lower camel case, and unhyphenated names without a matching reflection retain their exact HTML spelling. Term formation does not guess English word boundaries. A core-term collision receives a deterministic suffix; in this snapshot the data attribute is rdfhtml:dataAttribute because rdfhtml:data already represents character data.

Each definition records any rdfhtml:reflectedIdlName values and links to generated rdfhtml:AttributeContext resources. Contexts preserve applicability, description, original value-syntax text, and source links from the Living Standard attribute index. This metadata supports authoring and validation tools. A renderer MUST preserve direct strings and rdfhtml:attributeValue strings verbatim.

Child membership and ordering

A document or element is the ordering context for its direct children. rdfhtml:children points to one complete RDF Collection containing those children in immediate order. rdfhtml:hasChild points from parent to child. rdfhtml:childOf is its inverse and a subproperty of ord:inOrdering. The vocabulary classifies documents and elements as ord:TotalOrdering contexts and child node kinds as ord:Comparable resources [[INFERAL-ORDERING]].

Normalized view

Before validation, a processor MUST construct a normalized view that:

  1. traverses each rdfhtml:children collection, treating every member as a child and every consecutive pair as an ord:immediatelyPrecedes relation;
  2. treats child rdfhtml:childOf parent as parent rdfhtml:hasChild child;
  3. treats later ord:follows earlier as earlier ord:precedes later;
  4. treats later ord:immediatelyFollows earlier as earlier ord:immediatelyPrecedes later;
  5. treats every immediate-precedence edge as a broad-precedence edge as well; and
  6. starting from every asserted child of a parent, follows connected strict-precedence edges and adds their endpoints as children of that same parent.

The last rule is the bounded closure represented by the vocabulary's rdfhtml:hasChild / ord:precedes and rdfhtml:hasChild / ord:immediatelyPrecedes property chains. A processor MUST apply it even without general OWL inference. Consistent duplicate assertions are harmless. Opposing strict directions remain contradictory.

A rdfhtml:children value MUST be one finite, acyclic, well-formed RDF list. Its members MUST be distinct RDF resources and comprise the parent's complete child set. If collection and flat assertions coexist, their normalized membership and ordering MUST agree exactly.

Ordering validity

For every parent in a renderable document description, the normalized child ordering MUST:

ord:precedes and ord:follows constrain relative order without asserting adjacency. They MAY be mixed with immediate relations, but a processor MUST reject a graph whose constraints leave more than one possible child sequence rather than inventing a tie-break.

In the flat authoring form, when the intended constraint is only that one child occurs before or after another, authors SHOULD use ord:precedes or ord:follows. These broad relations are often more accurate than claiming immediate adjacency, especially when independently maintained graphs may insert other children between the two. Authors SHOULD NOT strengthen a broad ordering fact to an immediate relation merely to make validation easier. The complete data graph still MUST determine one linear sequence before it can be materialized.

Equivalent authoring forms

RDF Collections are the compact form for a complete child sequence. Converters SHOULD emit rdfhtml:children collections as their canonical representation.

Flat membership and ordering are useful when named children are contributed or edited independently, or when relative order is known without adjacency. This equivalent complete ordering does not require mutation of a shared list:

The inverse-direction form has the same normalized result:

Authors SHOULD use the flat form rather than an RDF list when they intend to assert only relative order. This lets separate graphs add children and ordering facts without rewriting a shared RDF list. With two children an ord:precedes assertion still determines the materialized sequence without claiming adjacency. With more children, the remaining constraints must remove every ambiguity.

Graph-to-DOM processing

Given an RDF 1.2 dataset and one selected rdfhtml:Document, a processor MUST:

  1. construct the normalized membership and ordering view;
  2. validate structural types, required values, parent ownership, and one unique child order for every container;
  3. create the document, document-type, element, text, comment, and attribute nodes identified by the graph;
  4. append each child in the derived sequence, using a template element's template contents as its child container; and
  5. establish the declared rdfhtml:base as the URL-resolution context for the resulting document.

Generated element classes determine HTML-namespace local names. A processor MUST preserve text and attribute string values as DOM data, not parse them as markup. It MUST NOT execute scripts merely to materialize the described structure. Whether scripts execute after a document is placed into a browsing context is outside this format.

A processor MUST report an error for missing or duplicate required values, unsupported concrete node classes, invalid custom-element or attribute names, malformed or inconsistent child collections, multiple parents, children on leaf or void nodes, invalid ordering, or a structure that violates the required document, html, head, and body cardinalities. A string serializer MUST additionally report data it cannot serialize without changing the represented DOM, such as an invalid HTML comment or a closing raw-text end-tag sequence inside raw-text data.

Faithful and publication outputs

A faithful HTML serialization contains only nodes and attributes described by the selected RDF/HTML structural subgraph. It MUST NOT inject an rdf-version attribute, metadata island, security banner, or runtime base node into that tree. The processor MUST return the declared base IRI separately so a consumer can supply the nominal document URL while parsing or hosting the serialization.

An implementation MAY additionally provide an augmented HTML/RDF publication output. That output can add rdf-version="1.2" and HTML/RDF carriers for input quads not consumed by structural processing. Such additions belong to the publication binding, not the faithful DOM. A runtime host MAY similarly add nodes marked data-rdfhtml-runtime-context; consumers MUST NOT present those nodes as described source structure.

HTML authoring conformance

Renderability establishes RDF/HTML structural consistency; it does not assert that the resulting document is conforming HTML. Generated content categories, attribute applicability, and value-syntax text are descriptive metadata. A processor MAY report diagnostics or apply a separately declared reviewed validation profile, but MUST NOT turn those generated descriptions into undocumented rejection rules.

Scope and limitations

RDF/HTML 0.1 models parsed HTML-namespace light DOM and template contents. MathML, SVG, shadow roots, and arbitrary detached DocumentFragment objects require future extension profiles. Customized built-in elements are represented by their ordinary generated element class plus an is attribute; autonomous custom elements use rdfhtml:CustomElement. Document-type public and system identifiers, CSSOM state, network resource bytes, parser-source locations, and byte-for-byte HTML syntax are outside this version.

A DOM-capable processor can use rdfhtml:attributeNamespace with namespace-aware DOM APIs. A string serializer that cannot preserve the binding MUST reject that occurrence rather than emit a deceptively unqualified attribute. Raw style element content remains text node data; RDF/HTML does not parse CSS into another model.

Versioned HTML vocabulary

Every RDF/HTML release MUST identify the dated HTML Living Standard snapshot used for its generated element classes and attribute definitions. Attribute definitions preserve their indexed local names, reflected Web IDL names and sources where available, and applicability contexts. A processor MAY support several snapshots. Absence from an older snapshot means only that its vocabulary did not define the term; it does not make a newer HTML feature obsolete.

Each renderable document explicitly declares a supported dated artifact with dcterms:conformsTo. This prevents an unversioned class IRI from silently changing meaning when the Living Standard snapshot moves. Additional conformance links MAY coexist and remain ordinary RDF annotations.

Unconditional category membership is expressed as an inspectable subclass axiom. Conditional membership MUST NOT be emitted as an unconditional rdfs:subClassOf assertion. Instead, the generated vocabulary records a rdfhtml:ConditionalCategoryMembership resource carrying the element class, category class, source, stable identifier, and original condition text or notation.

Content-category classification is semantic metadata. A processor does not need to retrieve or execute the generated ontology or reviewed conditional-rule module to materialize a document.

This specification is itself an [[IA2-HTML-RDF]] document. Its complete generated vocabulary, including core structure, syntax kinds, content categories, element classes, attribute definitions, applicability contexts, conditional classifications, and snapshot provenance, is asserted using HTML/RDF carriers in the document. The RDF Navigator can inspect or serialize that in-page dataset directly. The carrier block and the downloadable Turtle vocabulary are generated from the same source and MUST remain synchronized.

Conformance fixtures

The implementation-neutral fixture manifest covers a complete collection document, repeated structural facts across named graphs, partial descriptions, missing snapshot declarations, and contradictory ordering. Implementations can consume the Turtle and TriG inputs without depending on this project's JavaScript test harness.

Generated HTML element reference

This appendix is generated from the dated 2026-07-18 HTML Living Standard snapshot. It defines all 113 current conforming HTML-namespace element classes in that snapshot. Obsolete elements are excluded. Conditional category descriptions are provenance records, not unconditional subclass axioms. Expand an element to inspect its element-specific attribute definitions and the definitions that apply to all elements. A conditional marker preserves an applicability asterisk from the Living Standard index.

rdfhtml:A <a> 8 specific · 31 global

Represents the a element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content. Conditional categories: Interactive content (if the href attribute is present).

Element-specific 8

Applies to all elements 31

rdfhtml:Abbr <abbr> 1 specific · 31 global

Represents the abbr element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 1

Applies to all elements 31

rdfhtml:Address <address> 0 specific · 31 global

Represents the address element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Area <area> 9 specific · 31 global

Represents the area element in the HTML namespace. Its syntax kind is void. No unconditional indexed content-category memberships. Conditional categories: Flow content (if it is a descendant of a map element); Phrasing content (if it is a descendant of a map element).

Element-specific 9

Applies to all elements 31

rdfhtml:Article <article> 0 specific · 31 global

Represents the article element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Sectioning content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Aside <aside> 0 specific · 31 global

Represents the aside element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Sectioning content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Audio <audio> 8 specific · 31 global

Represents the audio element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Embedded content. Conditional categories: Interactive content (if the controls attribute is present); Palpable content (if the controls attribute is present).

Element-specific 8

Applies to all elements 31

rdfhtml:B <b> 0 specific · 31 global

Represents the b element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Base <base> 2 specific · 31 global

Represents the base element in the HTML namespace. Its syntax kind is void. Unconditional categories: Metadata content.

Element-specific 2

Applies to all elements 31

rdfhtml:Bdi <bdi> 0 specific · 31 global

Represents the bdi element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Bdo <bdo> 1 specific · 31 global

Represents the bdo element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 1

Applies to all elements 31

rdfhtml:Blockquote <blockquote> 1 specific · 31 global

Represents the blockquote element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Palpable content.

Element-specific 1

Applies to all elements 31

rdfhtml:Body <body> 0 specific · 31 global

Represents the body element in the HTML namespace. Its syntax kind is normal. No unconditional indexed content-category memberships.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Br <br> 0 specific · 31 global

Represents the br element in the HTML namespace. Its syntax kind is void. Unconditional categories: Flow content, Phrasing content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Button <button> 14 specific · 31 global

Represents the button element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Interactive content, Form-associated elements, Listed elements, Submittable elements, Autocapitalize-and-autocorrect inheriting elements, Labelable elements, Palpable content.

Element-specific 14

Applies to all elements 31

rdfhtml:Canvas <canvas> 2 specific · 31 global

Represents the canvas element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Embedded content, Palpable content.

Element-specific 2

Applies to all elements 31

rdfhtml:Caption <caption> 0 specific · 31 global

Represents the caption element in the HTML namespace. Its syntax kind is normal. No unconditional indexed content-category memberships.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Cite <cite> 0 specific · 31 global

Represents the cite element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Code <code> 0 specific · 31 global

Represents the code element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Col <col> 1 specific · 31 global

Represents the col element in the HTML namespace. Its syntax kind is void. No unconditional indexed content-category memberships.

Element-specific 1

Applies to all elements 31

rdfhtml:Colgroup <colgroup> 1 specific · 31 global

Represents the colgroup element in the HTML namespace. Its syntax kind is normal. No unconditional indexed content-category memberships.

Element-specific 1

Applies to all elements 31

rdfhtml:Data <data> 1 specific · 31 global

Represents the data element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 1

Applies to all elements 31

rdfhtml:Datalist <datalist> 0 specific · 31 global

Represents the datalist element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Dd <dd> 0 specific · 31 global

Represents the dd element in the HTML namespace. Its syntax kind is normal. No unconditional indexed content-category memberships.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Del <del> 2 specific · 31 global

Represents the del element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 2

Applies to all elements 31

rdfhtml:Details <details> 2 specific · 31 global

Represents the details element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Interactive content, Palpable content.

Element-specific 2

Applies to all elements 31

rdfhtml:Dfn <dfn> 1 specific · 31 global

Represents the dfn element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 1

Applies to all elements 31

rdfhtml:Dialog <dialog> 2 specific · 31 global

Represents the dialog element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content.

Element-specific 2

Applies to all elements 31

rdfhtml:Div <div> 0 specific · 31 global

Represents the div element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Dl <dl> 0 specific · 31 global

Represents the dl element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content. Conditional categories: Palpable content (if the element's children include at least one name-value group).

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Dt <dt> 0 specific · 31 global

Represents the dt element in the HTML namespace. Its syntax kind is normal. No unconditional indexed content-category memberships.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Em <em> 0 specific · 31 global

Represents the em element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Embed <embed> 4 specific · 31 global

Represents the embed element in the HTML namespace. Its syntax kind is void. Unconditional categories: Flow content, Phrasing content, Embedded content, Interactive content, Palpable content.

Element-specific 4

Applies to all elements 31

rdfhtml:Fieldset <fieldset> 3 specific · 31 global

Represents the fieldset element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Form-associated elements, Listed elements, Autocapitalize-and-autocorrect inheriting elements, Palpable content.

Element-specific 3

Applies to all elements 31

rdfhtml:Figcaption <figcaption> 0 specific · 31 global

Represents the figcaption element in the HTML namespace. Its syntax kind is normal. No unconditional indexed content-category memberships.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Figure <figure> 0 specific · 31 global

Represents the figure element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Form <form> 9 specific · 31 global

Represents the form element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Palpable content.

Element-specific 9

Applies to all elements 31

rdfhtml:H1 <h1> 0 specific · 31 global

Represents the h1 element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Heading content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:H2 <h2> 0 specific · 31 global

Represents the h2 element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Heading content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:H3 <h3> 0 specific · 31 global

Represents the h3 element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Heading content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:H4 <h4> 0 specific · 31 global

Represents the h4 element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Heading content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:H5 <h5> 0 specific · 31 global

Represents the h5 element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Heading content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:H6 <h6> 0 specific · 31 global

Represents the h6 element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Heading content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Head <head> 0 specific · 31 global

Represents the head element in the HTML namespace. Its syntax kind is normal. No unconditional indexed content-category memberships.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Header <header> 0 specific · 31 global

Represents the header element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Hgroup <hgroup> 0 specific · 31 global

Represents the hgroup element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Heading content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Hr <hr> 0 specific · 31 global

Represents the hr element in the HTML namespace. Its syntax kind is void. Unconditional categories: Flow content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Html <html> 0 specific · 31 global

Represents the html element in the HTML namespace. Its syntax kind is normal. No unconditional indexed content-category memberships.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:I <i> 0 specific · 31 global

Represents the i element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Iframe <iframe> 10 specific · 31 global

Represents the iframe element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Embedded content, Interactive content, Palpable content.

Element-specific 10

Applies to all elements 31

rdfhtml:Img <img> 14 specific · 31 global

Represents the img element in the HTML namespace. Its syntax kind is void. Unconditional categories: Flow content, Phrasing content, Embedded content, Form-associated elements, Palpable content. Conditional categories: Interactive content (if the usemap or controls attribute is present).

Element-specific 14

Applies to all elements 31

rdfhtml:Input <input> 35 specific · 31 global

Represents the input element in the HTML namespace. Its syntax kind is void. Unconditional categories: Flow content, Phrasing content, Form-associated elements, Listed elements, Submittable elements, Resettable elements, Autocapitalize-and-autocorrect inheriting elements, Labelable elements. Conditional categories: Interactive content (if the type attribute is not in the Hidden state); Palpable content (if the type attribute is not in the Hidden state).

Element-specific 35

Applies to all elements 31

rdfhtml:Ins <ins> 2 specific · 31 global

Represents the ins element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 2

Applies to all elements 31

rdfhtml:Kbd <kbd> 0 specific · 31 global

Represents the kbd element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Label <label> 1 specific · 31 global

Represents the label element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Interactive content, Form-associated elements, Palpable content.

Element-specific 1

Applies to all elements 31

rdfhtml:Legend <legend> 0 specific · 31 global

Represents the legend element in the HTML namespace. Its syntax kind is normal. No unconditional indexed content-category memberships.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Li <li> 1 specific · 31 global

Represents the li element in the HTML namespace. Its syntax kind is normal. No unconditional indexed content-category memberships.

Element-specific 1

Applies to all elements 31

rdfhtml:Main <main> 0 specific · 31 global

Represents the main element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Palpable content. Conditional categories: Flow content (if it is a hierarchically correct main element).

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Map <map> 1 specific · 31 global

Represents the map element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 1

Applies to all elements 31

rdfhtml:Mark <mark> 0 specific · 31 global

Represents the mark element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Menu <menu> 0 specific · 31 global

Represents the menu element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content. Conditional categories: Palpable content (if the element's children include at least one li element).

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Meta <meta> 5 specific · 31 global

Represents the meta element in the HTML namespace. Its syntax kind is void. Unconditional categories: Metadata content. Conditional categories: Flow content (if the itemprop attribute is present); Phrasing content (if the itemprop attribute is present).

Element-specific 5

Applies to all elements 31

rdfhtml:Meter <meter> 6 specific · 31 global

Represents the meter element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Labelable elements, Palpable content.

Element-specific 6

Applies to all elements 31

rdfhtml:Nav <nav> 0 specific · 31 global

Represents the nav element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Sectioning content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Noscript <noscript> 0 specific · 31 global

Represents the noscript element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Metadata content, Flow content, Phrasing content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Object <object> 6 specific · 31 global

Represents the object element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Embedded content, Form-associated elements, Listed elements, Palpable content. Conditional categories: Interactive content (interactive*).

Element-specific 6

Applies to all elements 31

rdfhtml:Ol <ol> 3 specific · 31 global

Represents the ol element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content. Conditional categories: Palpable content (if the element's children include at least one li element).

Element-specific 3

Applies to all elements 31

rdfhtml:Optgroup <optgroup> 2 specific · 31 global

Represents the optgroup element in the HTML namespace. Its syntax kind is normal. No unconditional indexed content-category memberships.

Element-specific 2

Applies to all elements 31

rdfhtml:Option <option> 4 specific · 31 global

Represents the option element in the HTML namespace. Its syntax kind is normal. No unconditional indexed content-category memberships.

Element-specific 4

Applies to all elements 31

rdfhtml:Output <output> 3 specific · 31 global

Represents the output element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Form-associated elements, Listed elements, Resettable elements, Autocapitalize-and-autocorrect inheriting elements, Labelable elements, Palpable content.

Element-specific 3

Applies to all elements 31

rdfhtml:P <p> 0 specific · 31 global

Represents the p element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Picture <picture> 0 specific · 31 global

Represents the picture element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Embedded content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Pre <pre> 0 specific · 31 global

Represents the pre element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Progress <progress> 2 specific · 31 global

Represents the progress element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Labelable elements, Palpable content.

Element-specific 2

Applies to all elements 31

rdfhtml:Q <q> 1 specific · 31 global

Represents the q element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 1

Applies to all elements 31

rdfhtml:Rp <rp> 0 specific · 31 global

Represents the rp element in the HTML namespace. Its syntax kind is normal. No unconditional indexed content-category memberships.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Rt <rt> 0 specific · 31 global

Represents the rt element in the HTML namespace. Its syntax kind is normal. No unconditional indexed content-category memberships.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Ruby <ruby> 0 specific · 31 global

Represents the ruby element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:S <s> 0 specific · 31 global

Represents the s element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Samp <samp> 0 specific · 31 global

Represents the samp element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Script <script> 10 specific · 31 global

Represents the script element in the HTML namespace. Its syntax kind is raw-text. Unconditional categories: Metadata content, Flow content, Phrasing content, Script-supporting elements.

Element-specific 10

Applies to all elements 31

rdfhtml:Section <section> 0 specific · 31 global

Represents the section element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Sectioning content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Select <select> 7 specific · 31 global

Represents the select element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Interactive content, Form-associated elements, Listed elements, Submittable elements, Resettable elements, Autocapitalize-and-autocorrect inheriting elements, Labelable elements, Palpable content.

Element-specific 7

Applies to all elements 31

rdfhtml:Selectedcontent <selectedcontent> 0 specific · 31 global

Represents the selectedcontent element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Phrasing content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Slot <slot> 1 specific · 31 global

Represents the slot element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content.

Element-specific 1

Applies to all elements 31

rdfhtml:Small <small> 0 specific · 31 global

Represents the small element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Source <source> 7 specific · 31 global

Represents the source element in the HTML namespace. Its syntax kind is void. No unconditional indexed content-category memberships.

Element-specific 7

Applies to all elements 31

rdfhtml:Span <span> 0 specific · 31 global

Represents the span element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Strong <strong> 0 specific · 31 global

Represents the strong element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Style <style> 3 specific · 31 global

Represents the style element in the HTML namespace. Its syntax kind is raw-text. Unconditional categories: Metadata content.

Element-specific 3

Applies to all elements 31

rdfhtml:Sub <sub> 0 specific · 31 global

Represents the sub element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Summary <summary> 0 specific · 31 global

Represents the summary element in the HTML namespace. Its syntax kind is normal. No unconditional indexed content-category memberships.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Sup <sup> 0 specific · 31 global

Represents the sup element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Table <table> 0 specific · 31 global

Represents the table element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Tbody <tbody> 0 specific · 31 global

Represents the tbody element in the HTML namespace. Its syntax kind is normal. No unconditional indexed content-category memberships.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Td <td> 3 specific · 31 global

Represents the td element in the HTML namespace. Its syntax kind is normal. No unconditional indexed content-category memberships.

Element-specific 3

Applies to all elements 31

rdfhtml:Template <template> 6 specific · 31 global

Represents the template element in the HTML namespace. Its syntax kind is template. Unconditional categories: Metadata content, Flow content, Phrasing content, Script-supporting elements.

Element-specific 6

Applies to all elements 31

rdfhtml:Textarea <textarea> 13 specific · 31 global

Represents the textarea element in the HTML namespace. Its syntax kind is escapable-raw-text. Unconditional categories: Flow content, Phrasing content, Interactive content, Form-associated elements, Listed elements, Submittable elements, Resettable elements, Autocapitalize-and-autocorrect inheriting elements, Labelable elements, Palpable content.

Element-specific 13

Applies to all elements 31

rdfhtml:Tfoot <tfoot> 0 specific · 31 global

Represents the tfoot element in the HTML namespace. Its syntax kind is normal. No unconditional indexed content-category memberships.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Th <th> 5 specific · 31 global

Represents the th element in the HTML namespace. Its syntax kind is normal. No unconditional indexed content-category memberships. Conditional categories: Interactive content (interactive*).

Element-specific 5

Applies to all elements 31

rdfhtml:Thead <thead> 0 specific · 31 global

Represents the thead element in the HTML namespace. Its syntax kind is normal. No unconditional indexed content-category memberships.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Time <time> 1 specific · 31 global

Represents the time element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 1

Applies to all elements 31

rdfhtml:Title <title> 0 specific · 31 global

Represents the title element in the HTML namespace. Its syntax kind is escapable-raw-text. Unconditional categories: Metadata content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Tr <tr> 0 specific · 31 global

Represents the tr element in the HTML namespace. Its syntax kind is normal. No unconditional indexed content-category memberships.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Track <track> 5 specific · 31 global

Represents the track element in the HTML namespace. Its syntax kind is void. No unconditional indexed content-category memberships.

Element-specific 5

Applies to all elements 31

rdfhtml:U <u> 0 specific · 31 global

Represents the u element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Ul <ul> 0 specific · 31 global

Represents the ul element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content. Conditional categories: Palpable content (if the element's children include at least one li element).

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Var <var> 0 specific · 31 global

Represents the var element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Palpable content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

rdfhtml:Video <video> 12 specific · 31 global

Represents the video element in the HTML namespace. Its syntax kind is normal. Unconditional categories: Flow content, Phrasing content, Embedded content, Palpable content. Conditional categories: Interactive content (if the controls attribute is present).

Element-specific 12

Applies to all elements 31

rdfhtml:Wbr <wbr> 0 specific · 31 global

Represents the wbr element in the HTML namespace. Its syntax kind is void. Unconditional categories: Flow content, Phrasing content.

Element-specific 0

  • No element-specific attributes.

Applies to all elements 31

Generated HTML attribute reference

This appendix is generated from the dated 2026-07-18 HTML Living Standard snapshot. It defines 144 current non-event-handler HTML attribute definitions and preserves all 179 indexed applicability and value-syntax contexts. The value syntax is descriptive metadata; RDF/HTML preserves the exact DOM attribute value as a string.

rdfhtml:abbr abbr 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name abbr. Reflected Web IDL names: abbr. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <th> Alternative label to use for the header cell when referencing the cell in other contexts. Value: Text*. Source: definition.
rdfhtml:accept accept 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name accept. Reflected Web IDL names: accept. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <input> Hint for expected file type in file upload controls. Value: Set of comma-separated tokens* consisting of valid MIME type strings with no parameters or audio/*, video/*, or image/*. Source: definition.
rdfhtml:acceptCharset accept-charset 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name accept-charset. Reflected Web IDL names: acceptCharset. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <form> Character encodings to use for form submission. Value: ASCII case-insensitive match for "UTF-8". Source: definition.
rdfhtml:accessKey accesskey 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name accesskey. Reflected Web IDL names: accessKey. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Keyboard shortcut to activate or focus element. Value: Ordered set of unique space-separated tokens, none of which are identical to another, each consisting of one code point in length. Source: definition.
rdfhtml:action action 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name action. Reflected Web IDL names: action. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <form> URL to use for form submission. Value: Valid non-empty URL potentially surrounded by spaces. Source: definition.
rdfhtml:allow allow 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name allow. Reflected Web IDL names: allow. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <iframe> Permissions policy to be applied to the iframe's contents. Value: Serialized permissions policy. Source: definition.
rdfhtml:allowFullscreen allowfullscreen 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name allowfullscreen. Reflected Web IDL names: allowFullscreen. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <iframe> Whether to allow the iframe's contents to use requestFullscreen(). Value: Boolean attribute. Source: definition.
rdfhtml:alpha alpha 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name alpha. Reflected Web IDL names: alpha. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <input> Allow the color's alpha component to be set. Value: Boolean attribute. Source: definition.
rdfhtml:alt alt 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name alt. Reflected Web IDL names: alt. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:as as 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name as. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <link> Destination for a preload request (for rel="preload" and rel="modulepreload"). Value: Preload destination, for rel="preload"; module preload destination, for rel="modulepreload". Source: definition.
rdfhtml:async async 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name async. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <script> Execute script when available, without blocking while fetching. Value: Boolean attribute. Source: definition.
rdfhtml:autocapitalize autocapitalize 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name autocapitalize. Reflected Web IDL names: autocapitalize. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Recommended autocapitalization behavior (for supported input methods). Value: "on"; "off"; "none"; "sentences"; "words"; "characters". Source: definition.
rdfhtml:autocomplete autocomplete 2 contexts

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name autocomplete. Reflected Web IDL names: autocomplete. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:autocorrect autocorrect 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name autocorrect. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Recommended autocorrection behavior (for supported input methods). Value: "on"; "off"; the empty string. Source: definition.
rdfhtml:autofocus autofocus 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name autofocus. Reflected Web IDL names: autofocus. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Automatically focus the element when the page is loaded. Value: Boolean attribute. Source: definition.
rdfhtml:autoplay autoplay 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name autoplay. Reflected Web IDL names: autoplay. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <audio>, <video> Hint that the media resource can be started automatically when the page is loaded. Value: Boolean attribute. Source: definition.
rdfhtml:blocking blocking 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name blocking. Reflected Web IDL names: blocking. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:charset charset 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name charset. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:checked checked 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name checked. Reflected Web IDL names: defaultChecked. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <input> Whether the control is checked. Value: Boolean attribute. Source: definition.
rdfhtml:cite cite 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name cite. Reflected Web IDL names: cite. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:class class 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name class. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Classes to which the element belongs. Value: Set of space-separated tokens. Source: definition.
rdfhtml:closedBy closedby 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name closedby. Reflected Web IDL names: closedBy. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <dialog> Which user actions will close the dialog. Value: "any"; "closerequest"; "none";. Source: definition.
rdfhtml:color color 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name color. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <link> Color to use when customizing a site's icon (for rel="mask-icon"). Value: CSS <color>. Source: definition.
rdfhtml:colorspace colorspace 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name colorspace. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <input> The color space of the serialized color. Value: "limited-srgb"; "display-p3". Source: definition.
rdfhtml:cols cols 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name cols. Reflected Web IDL names: cols. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <textarea> Maximum number of characters per line. Value: Valid non-negative integer greater than zero. Source: definition.
rdfhtml:colSpan colspan 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name colspan. Reflected Web IDL names: colSpan. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <td>, <th> Number of columns that the cell is to span. Value: Valid non-negative integer greater than zero. Source: definition.
rdfhtml:command command 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name command. Reflected Web IDL names: command. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <button> Indicates to the targeted element which action to take.. Value: "toggle-popover"; "show-popover"; "hide-popover"; "close"; "request-close"; "show-modal"; a custom command keyword. Source: definition.
rdfhtml:commandfor commandfor 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name commandfor. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:content content 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name content. Reflected Web IDL names: content. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:contenteditable contenteditable 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name contenteditable. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Whether the element is editable. Value: "true"; "false"; "plaintext-only"; the empty string. Source: definition.
rdfhtml:controls controls 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name controls. Reflected Web IDL names: controls. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:coords coords 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name coords. Reflected Web IDL names: coords. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <area> Coordinates for the shape to be created in an image map. Value: Valid list of floating-point numbers*. Source: definition.
rdfhtml:crossorigin crossorigin 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name crossorigin. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:dataAttribute data 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name data. Reflected Web IDL names: data. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <object> Address of the resource. Value: Valid non-empty URL potentially surrounded by spaces. Source: definition.
rdfhtml:dateTime datetime 2 contexts

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name datetime. Reflected Web IDL names: dateTime. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <del>, <ins> Date and (optionally) time of the change. Value: Valid date string with optional time. Source: definition.
  • <time> Machine-readable value. Value: Valid month string, valid date string, valid yearless date string, valid time string, valid local date and time string, valid time-zone offset string, valid global date and time string, valid week string, valid non-negative integer, or valid duration string. Source: definition.
rdfhtml:decoding decoding 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name decoding. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <img> Decoding hint to use when processing this image for presentation. Value: "sync"; "async"; "auto". Source: definition.
rdfhtml:default default 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name default. Reflected Web IDL names: default. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <track> Enable the track if no other text track is more suitable. Value: Boolean attribute. Source: definition.
rdfhtml:defer defer 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name defer. Reflected Web IDL names: defer. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:dir dir 2 contexts

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name dir. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements The text directionality of the element. Value: "ltr"; "rtl"; "auto". Source: definition.
  • <bdo> The text directionality of the element. Value: "ltr"; "rtl". Source: definition.
rdfhtml:dirName dirname 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name dirname. Reflected Web IDL names: dirName. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <input>, <textarea> Name of form control to use for sending the element's directionality in form submission. Value: Text*. Source: definition.
rdfhtml:disabled disabled 3 contexts

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name disabled. Reflected Web IDL names: disabled. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:download download 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name download. Reflected Web IDL names: download. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <a>, <area> Whether to download the resource instead of navigating to it, and its filename if so. Value: Text. Source: definition.
rdfhtml:draggable draggable 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name draggable. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Whether the element is draggable. Value: "true"; "false". Source: definition.
rdfhtml:enctype enctype 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name enctype. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <form> Entry list encoding type to use for form submission. Value: "application/x-www-form-urlencoded"; "multipart/form-data"; "text/plain". Source: definition.
rdfhtml:enterkeyhint enterkeyhint 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name enterkeyhint. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Hint for selecting an enter key action. Value: "enter"; "done"; "go"; "next"; "previous"; "search"; "send". Source: definition.
rdfhtml:fetchpriority fetchpriority 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name fetchpriority. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:for for 2 contexts

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name for. Reflected Web IDL names: htmlFor. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <label> Associate the label with form control. Value: ID*. Source: definition.
  • <output> Specifies controls from which the output was calculated. Value: Unordered set of unique space-separated tokens consisting of IDs*. Source: definition.
rdfhtml:form form 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name form. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:formAction formaction 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name formaction. Reflected Web IDL names: formAction. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <button>, <input> URL to use for form submission. Value: Valid non-empty URL potentially surrounded by spaces. Source: definition.
rdfhtml:formenctype formenctype 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name formenctype. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <button>, <input> Entry list encoding type to use for form submission. Value: "application/x-www-form-urlencoded"; "multipart/form-data"; "text/plain". Source: definition.
rdfhtml:formmethod formmethod 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name formmethod. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:formNoValidate formnovalidate 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name formnovalidate. Reflected Web IDL names: formNoValidate. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:formTarget formtarget 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name formtarget. Reflected Web IDL names: formTarget. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:headers headers 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name headers. Reflected Web IDL names: headers. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <td>, <th> The header cells for this cell. Value: Unordered set of unique space-separated tokens consisting of IDs*. Source: definition.
rdfhtml:headingOffset headingoffset 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name headingoffset. Reflected Web IDL names: headingOffset. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Offsets heading levels for descendants. Value: Valid non-negative integer between 0 and 8. Source: definition.
rdfhtml:headingReset headingreset 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name headingreset. Reflected Web IDL names: headingReset. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Prevents a heading offset computation from traversing beyond the element with the attribute. Value: Boolean attribute. Source: definition.
rdfhtml:height height 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name height. Reflected Web IDL names: height. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:hidden hidden 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name hidden. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Whether the element is relevant. Value: "until-found"; "hidden"; the empty string. Source: definition.
rdfhtml:high high 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name high. Reflected Web IDL names: high. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <meter> Low limit of high range. Value: Valid floating-point number*. Source: definition.
rdfhtml:href href 3 contexts

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name href. Reflected Web IDL names: href. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <a>, <area> Address of the hyperlink. Value: Valid URL potentially surrounded by spaces. Source: definition.
  • <link> Address of the hyperlink. Value: Valid non-empty URL potentially surrounded by spaces. Source: definition.
  • <base> Document base URL. Value: Valid URL potentially surrounded by spaces. Source: definition.
rdfhtml:hreflang hreflang 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name hreflang. Reflected Web IDL names: hreflang. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:httpEquiv http-equiv 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name http-equiv. Reflected Web IDL names: httpEquiv. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <meta> Pragma directive. Value: "content-type"; "default-style"; "refresh"; "x-ua-compatible"; "content-security-policy". Source: definition.
rdfhtml:id id 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name id. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements The element's ID. Value: Text*. Source: definition.
rdfhtml:imageSizes imagesizes 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name imagesizes. Reflected Web IDL names: imageSizes. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <link> Image sizes for different page layouts (for rel="preload"). Value: Valid source size list. Source: definition.
rdfhtml:imageSrcset imagesrcset 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name imagesrcset. Reflected Web IDL names: imageSrcset. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <link> Images to use in different situations, e.g., high-resolution displays, small monitors, etc. (for rel="preload"). Value: Comma-separated list of image candidate strings. Source: definition.
rdfhtml:inert inert 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name inert. Reflected Web IDL names: inert. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Whether the element is inert.. Value: Boolean attribute. Source: definition.
rdfhtml:inputmode inputmode 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name inputmode. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Hint for selecting an input modality. Value: "none"; "text"; "tel"; "email"; "url"; "numeric"; "decimal"; "search". Source: definition.
rdfhtml:integrity integrity 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name integrity. Reflected Web IDL names: integrity. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:is is 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name is. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Creates a customized built-in element. Value: Valid custom element name of a defined customized built-in element. Source: definition.
rdfhtml:isMap ismap 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name ismap. Reflected Web IDL names: isMap. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <img> Whether the image is a server-side image map. Value: Boolean attribute. Source: definition.
rdfhtml:itemid itemid 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name itemid. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Global identifier for a microdata item. Value: Valid URL potentially surrounded by spaces. Source: definition.
rdfhtml:itemprop itemprop 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name itemprop. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Property names of a microdata item. Value: Unordered set of unique space-separated tokens consisting of valid absolute URLs, defined property names, or text*. Source: definition.
rdfhtml:itemref itemref 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name itemref. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Referenced elements. Value: Unordered set of unique space-separated tokens consisting of IDs*. Source: definition.
rdfhtml:itemscope itemscope 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name itemscope. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Introduces a microdata item. Value: Boolean attribute. Source: definition.
rdfhtml:itemtype itemtype 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name itemtype. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Item types of a microdata item. Value: Unordered set of unique space-separated tokens consisting of valid absolute URLs*. Source: definition.
rdfhtml:kind kind 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name kind. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <track> The type of text track. Value: "subtitles"; "captions"; "descriptions"; "chapters"; "metadata". Source: definition.
rdfhtml:label label 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name label. Reflected Web IDL names: label. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:lang lang 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name lang. Reflected Web IDL names: lang. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Language of the element. Value: Valid BCP 47 language tag or the empty string. Source: definition.
rdfhtml:list list 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name list. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:loading loading 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name loading. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:loop loop 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name loop. Reflected Web IDL names: loop. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:low low 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name low. Reflected Web IDL names: low. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <meter> High limit of low range. Value: Valid floating-point number*. Source: definition.
rdfhtml:max max 2 contexts

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name max. Reflected Web IDL names: max. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:maxLength maxlength 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name maxlength. Reflected Web IDL names: maxLength. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:media media 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name media. Reflected Web IDL names: media. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:method method 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name method. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <form> Variant to use for form submission. Value: "get"; "post"; "dialog". Source: definition.
rdfhtml:min min 2 contexts

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name min. Reflected Web IDL names: min. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:minLength minlength 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name minlength. Reflected Web IDL names: minLength. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:multiple multiple 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name multiple. Reflected Web IDL names: multiple. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:muted muted 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name muted. Reflected Web IDL names: defaultMuted. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:name name 7 contexts

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name name. Reflected Web IDL names: name. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:noModule nomodule 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name nomodule. Reflected Web IDL names: noModule. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <script> Prevents execution in user agents that support module scripts. Value: Boolean attribute. Source: definition.
rdfhtml:nonce nonce 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name nonce. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Cryptographic nonce used in Content Security Policy checks [CSP]. Value: Text. Source: definition.
rdfhtml:noValidate novalidate 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name novalidate. Reflected Web IDL names: noValidate. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <form> Bypass form control validation for form submission. Value: Boolean attribute. Source: definition.
rdfhtml:open open 2 contexts

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name open. Reflected Web IDL names: open. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:optimum optimum 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name optimum. Reflected Web IDL names: optimum. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <meter> Optimum value in gauge. Value: Valid floating-point number*. Source: definition.
rdfhtml:pattern pattern 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name pattern. Reflected Web IDL names: pattern. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <input> Pattern to be matched by the form control's value. Value: Regular expression matching the JavaScript Pattern production. Source: definition.
rdfhtml:ping ping 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name ping. Reflected Web IDL names: ping. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <a>, <area> URLs to ping. Value: Set of space-separated tokens consisting of valid non-empty URLs. Source: definition.
rdfhtml:placeholder placeholder 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name placeholder. Reflected Web IDL names: placeholder. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:playsInline playsinline 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name playsinline. Reflected Web IDL names: playsInline. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <video> Encourage the user agent to display video content within the element's playback area. Value: Boolean attribute. Source: definition.
rdfhtml:popover popover 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name popover. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Makes the element a popover element. Value: "auto"; "manual"; "hint"; the empty string. Source: definition.
rdfhtml:popovertarget popovertarget 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name popovertarget. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:popovertargetaction popovertargetaction 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name popovertargetaction. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <button>, <input> Indicates whether a targeted popover element is to be toggled, shown, or hidden. Value: "toggle"; "show"; "hide". Source: definition.
rdfhtml:poster poster 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name poster. Reflected Web IDL names: poster. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <video> Poster frame to show prior to video playback. Value: Valid non-empty URL potentially surrounded by spaces. Source: definition.
rdfhtml:preload preload 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name preload. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <audio>, <video> Hints how much buffering the media resource will likely need. Value: "none"; "metadata"; "auto"; the empty string. Source: definition.
rdfhtml:readOnly readonly 2 contexts

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name readonly. Reflected Web IDL names: readOnly. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <input>, <textarea> Whether to allow the value to be edited by the user. Value: Boolean attribute. Sources: definition 1, definition 2.
  • form associated custom elements Affects willValidate, plus any behavior added by the custom element author. Value: Boolean attribute.
rdfhtml:referrerpolicy referrerpolicy 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name referrerpolicy. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:rel rel 2 contexts

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name rel. Reflected Web IDL names: rel, relList. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <a>, <area> Relationship between the location in the document containing the hyperlink and the destination resource. Value: Unordered set of unique space-separated tokens*. Source: definition.
  • <link> Relationship between the document containing the hyperlink and the destination resource. Value: Unordered set of unique space-separated tokens*. Source: definition.
rdfhtml:required required 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name required. Reflected Web IDL names: required. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:reversed reversed 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name reversed. Reflected Web IDL names: reversed. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <ol> Number the list backwards. Value: Boolean attribute. Source: definition.
rdfhtml:rows rows 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name rows. Reflected Web IDL names: rows. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <textarea> Number of lines to show. Value: Valid non-negative integer greater than zero. Source: definition.
rdfhtml:rowSpan rowspan 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name rowspan. Reflected Web IDL names: rowSpan. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <td>, <th> Number of rows that the cell is to span. Value: Valid non-negative integer. Source: definition.
rdfhtml:sandbox sandbox 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name sandbox. Reflected Web IDL names: sandbox. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <iframe> Security rules for nested content. Value: Unordered set of unique space-separated tokens, ASCII case-insensitive, consisting of "allow-downloads""allow-forms""allow-modals""allow-orientation-lock""allow-pointer-lock""allow-popups""allow-popups-to-escape-sandbox""allow-presentation""allow-same-origin""allow-scripts""allow-top-navigation""allow-top-navigation-by-user-activation""allow-top-navigation-to-custom-protocols". Source: definition.
rdfhtml:scope scope 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name scope. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <th> Specifies which cells the header cell applies to. Value: "row"; "col"; "rowgroup"; "colgroup". Source: definition.
rdfhtml:selected selected 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name selected. Reflected Web IDL names: defaultSelected. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <option> Whether the option is selected by default. Value: Boolean attribute. Source: definition.
rdfhtml:shadowRootClonable shadowrootclonable 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name shadowrootclonable. Reflected Web IDL names: shadowRootClonable. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <template> Sets clonable on a declarative shadow root. Value: Boolean attribute. Source: definition.
rdfhtml:shadowRootCustomElementRegistry shadowrootcustomelementregistry 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name shadowrootcustomelementregistry. Reflected Web IDL names: shadowRootCustomElementRegistry. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <template> Enables declarative shadow roots to indicate they will use a custom element registry. Value: Boolean attribute. Source: definition.
rdfhtml:shadowRootDelegatesFocus shadowrootdelegatesfocus 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name shadowrootdelegatesfocus. Reflected Web IDL names: shadowRootDelegatesFocus. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <template> Sets delegates focus on a declarative shadow root. Value: Boolean attribute. Source: definition.
rdfhtml:shadowrootmode shadowrootmode 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name shadowrootmode. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <template> Enables streaming declarative shadow roots. Value: "open"; "closed". Source: definition.
rdfhtml:shadowRootSerializable shadowrootserializable 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name shadowrootserializable. Reflected Web IDL names: shadowRootSerializable. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <template> Sets serializable on a declarative shadow root. Value: Boolean attribute. Source: definition.
rdfhtml:shadowrootslotassignment shadowrootslotassignment 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name shadowrootslotassignment. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <template> Sets slot assignment on a declarative shadow root. Value: "named"; "manual". Source: definition.
rdfhtml:shape shape 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name shape. Reflected Web IDL names: shape. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <area> The kind of shape to be created in an image map. Value: "circle"; "default"; "poly"; "rect". Source: definition.
rdfhtml:size size 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name size. Reflected Web IDL names: size. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:sizes sizes 2 contexts

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name sizes. Reflected Web IDL names: sizes. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <link> Sizes of the icons (for rel="icon"). Value: Unordered set of unique space-separated tokens, ASCII case-insensitive, consisting of sizes*. Source: definition.
  • <img>, <source> Image sizes for different page layouts. Value: Valid source size list. Sources: definition 1, definition 2.
rdfhtml:slot slot 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name slot. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements The element's desired slot. Value: Text. Source: definition.
rdfhtml:span span 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name span. Reflected Web IDL names: span. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:spellcheck spellcheck 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name spellcheck. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Whether the element is to have its spelling and grammar checked. Value: "true"; "false"; the empty string. Source: definition.
rdfhtml:src src 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name src. Reflected Web IDL names: src. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:srcdoc srcdoc 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name srcdoc. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <iframe> A document to render in the iframe. Value: The source of an iframe srcdoc document*. Source: definition.
rdfhtml:srclang srclang 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name srclang. Reflected Web IDL names: srclang. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <track> Language of the text track. Value: Valid BCP 47 language tag. Source: definition.
rdfhtml:srcset srcset 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name srcset. Reflected Web IDL names: srcset. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <img>, <source> Images to use in different situations, e.g., high-resolution displays, small monitors, etc.. Value: Comma-separated list of image candidate strings. Sources: definition 1, definition 2.
rdfhtml:start start 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name start. Reflected Web IDL names: start. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <ol> Starting value of the list. Value: Valid integer. Source: definition.
rdfhtml:step step 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name step. Reflected Web IDL names: step. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <input> Granularity to be matched by the form control's value. Value: Valid floating-point number greater than zero, or "any". Source: definition.
rdfhtml:style style 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name style. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Presentational and formatting instructions. Value: CSS declarations*. Source: definition.
rdfhtml:tabIndex tabindex 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name tabindex. Reflected Web IDL names: tabIndex. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Whether the element is focusable and sequentially focusable, and the relative order of the element for the purposes of sequential focus navigation. Value: Valid integer. Source: definition.
rdfhtml:target target 3 contexts

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name target. Reflected Web IDL names: target. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <a>, <area> Navigable for hyperlink navigation. Value: Valid navigable target name or keyword. Source: definition.
  • <base> Default navigable for hyperlink navigation and form submission. Value: Valid navigable target name or keyword. Source: definition.
  • <form> Navigable for form submission. Value: Valid navigable target name or keyword. Source: definition.
rdfhtml:title title 5 contexts

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name title. Reflected Web IDL names: title. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:translate translate 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name translate. No reflected Web IDL name is indexed for this attribute. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Whether the element is to be translated when the page is localized. Value: "yes"; "no"; the empty string. Source: definition.
rdfhtml:type type 6 contexts

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name type. Reflected Web IDL names: type. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:useMap usemap 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name usemap. Reflected Web IDL names: useMap. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <img> Name of image map to use. Value: Valid hash-name reference*. Source: definition.
rdfhtml:value value 5 contexts

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name value. Reflected Web IDL names: defaultValue, value. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:width width 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name width. Reflected Web IDL names: width. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

rdfhtml:wrap wrap 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name wrap. Reflected Web IDL names: wrap. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • <textarea> How the value of the form control is to be wrapped for form submission. Value: "soft"; "hard". Source: definition.
rdfhtml:writingSuggestions writingsuggestions 1 context

This rdfhtml:AttributeDefinition and owl:DatatypeProperty maps to the HTML local name writingsuggestions. Reflected Web IDL names: writingSuggestions. Its direct value and expanded rdfhtml:attributeValue remain exact DOM strings.

  • all HTML elements Whether the element can offer writing suggestions or not.. Value: "true"; "false"; the empty string. Source: definition.

Snapshot provenance

The dated snapshot records conforming HTML-namespace elements, non-event-handler HTML attributes, their contextual applicability and value syntax, definition URLs, syntax kinds, content categories, condition text, source URLs, and source-document SHA-256 digests. Obsolete elements are excluded. Text, custom elements, and MathML and SVG participants found in WHATWG's category tables are retained separately.

Snapshot date
2026-07-18
Element source
HTML Living Standard element index
Attribute source
HTML Living Standard attribute index
Category source
Element content-category index
Syntax source
HTML syntax kinds
Snapshot data
Dated JSON snapshot
Vocabulary
Generated Turtle vocabulary
Reviewed rules
Conditional SHACL-AF module

A separate reviewed module formalizes straightforward attribute-presence cases for a, audio, video, img, and meta, plus direct li-child conditions for menu, ol, and ul. More prose-oriented conditions remain sourced descriptions rather than misleading unconditional axioms.

In particular, the area-inside-map condition is not yet a reviewed rule. Raw RDF can express ancestry through compact list spines or through normalized flat membership, so a rule targeting only one path would miss valid documents. It remains explicit sourced classification data until a portable rule can cover both encodings and their normalized equivalence.

Relationship to HTMLVoc

The HTML vocabulary project (HTMLVoc) [[HTMLVOC]] is the closest prior attempt known to this proposal. RDF/HTML adopts its central premise that HTML documents and DOM nodes can be represented, queried, validated, transformed, and serialized as RDF resources. RDF/HTML is an independent exploratory profile, not a new version of HTMLVoc or a compatible serialization.

ConcernHTMLVocRDF/HTML 0.1
Element vocabularyHand-authored RDF/OWL vocabulary.Dated mechanical extraction from WHATWG with exact provenance.
Child orderNumbered properties such as rdf:_1.Parent-scoped membership and strict-precedence relations.
AttributesOntology properties for HTML attributes.Generated datatype properties with contextual applicability and value-syntax provenance; expanded occurrence nodes remain available for annotations and extensions.
Content categoriesRicher hand-authored OWL equivalence expressions.Unconditional generated axioms, explicit conditional facts, and separately reviewed rules.
ProcessingSHACL-AF and SPARQL functions materialize fragments.A bounded graph-to-DOM algorithm independent of ontology retrieval.