existing rel values
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This page contains tables of known HTML rel values from specifications, formats, proposals, brainstorms, and non-trivial POSH usage in the wild. In addition, dropped and rejected values are listed at the end for comprehensiveness.
usage: see how is 'rel' used. Regarding rev, see: should 'rev' even be used.
This page is also the official rel registry (WHATWG HTML (original link), W3C HTML5). Add new and proposed rel values to the following section:
formats
These rel values are defined formats from specifications (HTML 4, microformats) are thus are recommended for general use. Alphabetically ordered by value.
Note:
- Do not add proposed rel values for HTML5 here, add them to the HTML5 link type extensions table.
- Do not add rel values you find in the wild to this table of rel formats, instead add them to the table in the POSH section.
- Do not add non-HTML rel values you find to this table of rel formats, instead add them to the table in the non HTML rel values section.
- Do not add rel values from obsolete/superceded proposals or drafts, instead add them to the table in the "dropped" section.
Sources:
- W3C Recommendations:
- HTML 4.01 section 6.12 Link types (HTML4 Link types)
- Gleaning Resource Descriptions from Dialects of Languages (GRDDL)
- microformats specifications
| Keyword | Effect on link
|
Effect on a, area
|
Brief description (from the relevant specification where possible) |
Link to defining specification |
|---|---|---|---|---|
| acquaintance | not allowed | external relation | the person represented by the current document considers the person represented by the referenced document to be an acquaintance | XFN |
| alternate | external resource | external relation | Designates substitute versions for the document in which the link occurs. When used together with the lang attribute, it implies a translated version of the document. When used together with the media attribute, it implies a version designed for a different medium (or media).
|
HTML4 Link types |
| appendix | allowed | allowed | Refers to a document serving as an appendix in a collection of documents. | HTML4 Link types
|
| bookmark | not allowed | allowed | Refers to a bookmark. A bookmark is a link to a key entry point within an extended document. The title attribute may be used, for example, to label the bookmark. Note that several bookmarks may be defined in each document.
|
HTML4 Link types |
| chapter | allowed | allowed | Refers to a document serving as a chapter in a collection of documents. | HTML4 Link types |
| child | external relation | external relation | The referenced person is a child of the person represented by the current document. It may also indicate that the target document is a hierarchical child, or subdocument, of the current document. | XFN, HTML 4.0 Specification |
| colleague | not allowed | external relation | the referenced person is a colleague of the person represented by the current document | XFN |
| contact | not allowed | external relation | the person represented by the current document considers the person represented by the referenced document to be a contact | XFN |
| contents | allowed | allowed | Refers to a document serving as a table of contents. Some user agents also support the synonym ToC (from "Table of Contents"). | HTML4 Link types |
| copyright | allowed | allowed | Refers to a copyright statement for the current document. | HTML4 Link types |
| co-resident | not allowed | external relation | the referenced person lives in the same residence as the person represented by the current document | XFN |
| co-worker | not allowed | external relation | the referenced person is a co-worker of the person represented by the current document | XFN |
| crush | not allowed | external relation | this person considers the referenced person to be a crush (i.e. has a crush on the referenced person) | XFN |
| date | not allowed | external relation | this person considers the referenced person to be a date (i.e. is dating the referenced person) | XFN |
| friend | not allowed | external relation | the person represented by the current document considers the person represented by the referenced document to be a friend | XFN |
| glossary | allowed | allowed | Refers to a document providing a list of terms and their definitions that pertain to the current document. | HTML4 Link types |
| help | allowed | allowed | Refers to a document offering help (more information, links to other sources information, etc.) | HTML4 Link types |
| its-rules | allowed | not allowed | Refers to a document with external ITS rules. | Internationalization Tag Set (ITS) Version 2.0 |
| kin | not allowed | external relation | the referenced person is part of the extended family of the person represented by the current document | XFN |
| license | allowed | allowed | …indicates that the [referenced document] is a license for the current page. | rel-license |
| me | external relation | external relation | the referenced document represents the same person as does the current document | XFN |
| met | not allowed | external relation | this person has met the referenced person | XFN |
| muse | not allowed | external relation | the referenced person inspires the person represented by the current document | XFN |
| neighbor | not allowed | external relation | the referenced person lives nearby the person represented by the current document | XFN |
| next | external relation | external relation | Refers to the next document in a linear sequence of documents. User agents may choose to preload the "next" document, to reduce the perceived load time. | HTML4 Link types |
| nofollow | not allowed | external relation | indicates that the destination of that hyperlink SHOULD NOT be afforded any additional weight or ranking by user agents which perform link analysis upon web pages (e.g. search engines). | rel-nofollow |
| parent | external relation | external relation | The referenced person is a parent of the person represented by the current document. It may also indicate that the target document is the hierarchical parent, or container, of the current document. | XFN, HTML 4.0 Specification |
| prev | external relation | external relation | Refers to the previous document in an ordered series of documents. Some user agents also support the synonym "Previous". | HTML4 Link types |
| previous | external relation | external relation | Synonym of prev
|
HTML4 Link types |
| section | allowed | allowed | Refers to a document serving as a section in a collection of documents. | HTML4 Link types |
| sibling | not allowed | external relation | the referenced person is a sibling of the person represented by the current document | XFN |
| spouse | not allowed | external relation | the referenced person is a spouse of the person represented by the current document | XFN |
| start | allowed | allowed | Refers to the first document in a collection of documents. This link type tells search engines which document is considered by the author to be the starting point of the collection. | HTML4 Link types |
| stylesheet | external resource | not allowed | a style sheet for the current document used with the invisible <link href> element which is not ideal for content relationships. Content relationships should be user visible and thus uses with <a href> are strongly preferred. Unfortunately the use of stylesheet in user visible content like <a href> appears to be strictly theoretical. |
HTML4 Link types |
| subsection | allowed | allowed | Refers to a document serving as a subsection in a collection of documents. | HTML4 Link types |
| sweetheart | not allowed | external relation | this person considers the referenced person to be their sweetheart | XFN |
| tag | not allowed | allowed | …indicates that the [referenced document] is an author-designated "tag" (or keyword/subject) for the current page. | rel-tag |
| toc | allowed | allowed | Synonym of contents (from "Table Of Contents")
|
HTML4 Link types |
| transformation | allowed | allowed | Relates a source document to a transformation, usually represented in XSLT, that relates the source document syntax to the RDF graph syntax. Used in GRDDL | GRDDL |
notes
rel="alternate"can take further meaning from additional attributes, such asrel="alternate" lang="fr"(French language version of this page)rel="alternate" media="print"(printable version of this page)rel="alternate" media="handheld"(version of the page intended or better for handheld/portable devices like PDAs, cell phones, etc.)
- Synonyms such as "previous", "toc" are not as widely supported as the main term.
proposals
A few rel values have been developed as drafts as a result of going through most of the microformats process, and are thus listed here for your serious consideration. You may use these values, and if you find any problems with them please point them out on the respective "issues" page for the rel value.
| rel value | summary | proposed in | external spec (if any) |
|---|---|---|---|
| pronunciation | …indicates that the destination of the 'link' element is a document providing a pronunciation lexicon for speech-synthesis purposes. | rel-pronunciation | |
| directory | …indicates that the destination of the hyperlink is a directory listing containing an entry for the current page. | rel-directory | |
| enclosure | …indicates that the destination of that hyperlink is intended to be downloaded and cached. | rel-enclosure | RFC4287 |
| home | …indicates that the [referenced document] is the homepage of the site in which the current page appears. | rel-home | |
| payment | …indicates that the destination of the hyperlink provides a way to show or give support (e.g. financial) for the current page | rel-payment | |
| vcs-* | …indicates that the destination of the hyperlink is the location of a Version Control System repository related to that page. | rel=vcs-* |
HTML5 link type extensions
The following values are registered as link type extensions per the requirements in the WHATWG HTML spec and the requirements in the W3C HTML5 spec.
Before you register a new value:
- Please check the Formats table and DO NOT re-register rel values that are already there. Please note that the W3C HTML WG has made a Decision to drop
index,up,firstandlastfrom the HTML5 spec itself. - Please check the Dropped table and DO NOT register values that are already there. If you believe a rel value was dropped from another specification without prejudice, please provide link/cite to explicit text/decision stating as such, e.g. the value was merely postponed, or perhaps expected to be spun-out into its own spec from the group developing that specification.
Note that entries in the Formats table and entries that are already in HTML5 as built-in keywords are also considered extensions with the "Ratified" status.
Please make sure that registrations added here have all the required data filled in including:
- "Effect on link"
- "Effect on a and area" and
- a link to a spec that documents the keyword as an HTML
relkeyword. (A spec that merely defines the file format of the link target but does not define therelkeyword for use in HTML is not the kind of spec that is being required here.)
Entries lacking any of the above required data will likely be removed.
Changes to this registry will not be reflected in validators in real time. But validators will typically get automatically updated with the changes within one week or so
| Keyword | Effect on link
|
Effect on a, area
|
Brief description | Link to specification | Synonyms | Status
|
|---|---|---|---|---|---|---|
| about | Hyperlink | Hyperlink | The resource linked to contains information about the current page. | RFC6903 | It might combine with rel-me or rel-author in links to an "about" section focused on an author | proposed |
| amphtml | Hyperlink | Hyperlink | Specify an alternate version of the document written in AMP HTML | AMP HTML documentation | could be combined with rel=alternate | proposed |
| apple-touch-icon | External Resource | Not allowed | Specify a Webpage Icon for a “Web Clip”, or “touch icon”, for mobile devices (not limited to Apple devices). | Apple's Safari Web Content Guide | probably redundant with rel=icon | proposed |
| apple-touch-icon-precomposed | External Resource | Not allowed | Specify a Webpage Icon for a “Web Clip”, or “touch icon”, for mobile devices (not limited to Apple devices). | Apple's Safari Web Content Guide | probably redundant with rel=icon | proposed |
| apple-touch-startup-image | External Resource | Not allowed | Specify a splashscreen for Web apps on iOS Safari | Apple's Safari Web Content Guide | maybe redundant with rel=icon with the sizes attribute? | proposed |
| archived | External Resource | Hyperlink Annotation | The target resource is archived and kept largely or solely for historical purposes. | rel="archived" description | proposed | |
| atproto | external relation | external relation | indicates the link is an ATProto account handle | IndieWeb: rel-atproto | proposed | |
| attachment | Hyperlink | Hyperlink | The resource linked to is "attached" to this document, similar to email attachments. Used in WordPress. | No formal specification | proposed | |
| authn | external relation | external relation | use only the referenced profiles (URLs) for authenticating the current page/site/user e.g. via rel-me | IndieWeb: rel-authn | proposed | |
| authorization_endpoint | External Resource | Not allowed | Specify a hosted authorization server | IndieAuth spec | proposed | |
| canonical | Hyperlink | Hyperlink | Specifies the canonical URL for the current document in order to help avoid duplicate content. | Canonical meta tag Canonicalization at Google Webmaster Central Microsoft Webmaster Center Yahoo! Search Blog | proposed | |
| category | Hyperlink | Hyperlink | Refers to a category assigned to the current document or post. Implemented by WordPress for indicating a relation between a blog post and a category. | rel-category | proposed | |
| code-repository | Hyperlink | Hyperlink | indicates a code repository location. For link, it specifically indicates, in the case of server-generated content, the location of source code responsible for the generation of the current page, or, in the case of static files, where copies of the current page are housed). If the specific data/content built up at the page is stored separately from the generator (e.g., the code for a CMS vs. the specific CMS instance's SQL tables or JSON data files), this only refers to the generator and content-repository should be used to indicate the location for the storage of content. Otherwise, the code repository can be considered as also including the content. While the repository should contain its own license file, the code-license rel-value is proposed as a direct pointer to the license (see also content-license). | proposed | ||
| code-license | Hyperlink | Hyperlink | indicates a license for code (a proposed broader replacement for jslicense). For link, it specifically indicates, in the case of server-generated content, the location of the license for all source code responsible for the generation of the current page, or, in the case of static files, the location of the license for all of these files). If the specific data/content built up at the page is stored separately from the generator (e.g., the code for a CMS vs. the specific CMS instance's SQL tables or JSON data files), this only refers to the generator and content-license should be used to indication the license for the content. Otherwise, code-license can be considered as also covering the license of the content. Pointing to the repository containing the static or generator code files should be done with code-repository (and content-repository for any separate content). | proposed
| ||
| component | External Resource | Not allowed | Specify an HTML document that is treated as a component of this document. | Web Components | proposed | |
| chrome-webstore-item | External Resource | Not allowed | Link tag to declare for app and extensions inline installations hosted in the Chrome Web Store. | Using Inline Installation | proposed | |
| content-repository | Hyperlink | Hyperlink | indicates a repository housing data content. For link, it specifically indicates, in the case of server-generated content, the location where separately housed data files used to populate the current page are stored (otherwise "code-repository" is sufficient to include content as well as code). If the specific data/content built up at the page is stored separately from the generator (e.g., the code for a CMS vs. the specific CMS instance's SQL tables or JSON data files), this only refers to the data/content files and code-repository should be used to indicate the location for the storage of the generator source files. Otherwise, code-repository can be considered as also including the content instead. While the repository should contain its own license file, the content-license rel-value is proposed as a direct pointer to the license (see also code-license). | proposed | ||
| content-license | Hyperlink | Hyperlink | indicates a license for data content. For link, it specifically indicates, in the case of server-generated content, the location of the license for all separately housed data files used to populate the current page are stored, (otherwise "code-license" is sufficient to cover the license of content as well as code)). If the specific data/content built up at the page is stored separately from the generator (e.g., the code for a CMS vs. the specific CMS instance's SQL tables or JSON data files), this only refers to the data/content files and code-license should be used to indication the license for the generator source files. Otherwise, code-license can be considered as also covering the license of the content. Pointing to the repository containing the data files should be done with content-repository (and code-repository for the static or generator code files). | proposed
| ||
| DCTERMS.conformsTo | External Resource | Not allowed | An established standard to which the described resource conforms. Requires Dublin Core namespace declaration: |
DCMI Metadata Terms | It may be replaced by the literal value in form of <meta name="DCTERMS.conformsTo" content="..." />
|
proposed |
| DCTERMS.contributor | External Resource | Not allowed | An entity responsible for making contributions to the resource. Examples include a person, an organization, or a service. Requires Dublin Core namespace declaration: |
DCMI Metadata Terms | It may be replaced by the literal value in form of <meta name="DCTERMS.contributor" content="..." />
|
proposed |
| DCTERMS.creator | External Resource | Not allowed | An entity primarily responsible for making the resource. Examples include a person, an organization, or a service. Requires Dublin Core namespace declaration: |
DCMI Metadata Terms | It may be replaced by the literal value in form of <meta name="DCTERMS.creator" content="..." />
|
proposed |
| DCTERMS.description | External Resource | Not allowed | An account of the resource. Description may include but is not limited to: an abstract, a table of contents, a graphical representation, or a free-text account of the resource. Requires Dublin Core namespace declaration: |
DCMI Metadata Terms | It may be replaced by the literal value in form of <meta name="DCTERMS.description" content="..." />
|
proposed |
| DCTERMS.hasFormat | External Resource | Not allowed | A related resource that is substantially the same as the pre-existing described resource, but in another format. Requires Dublin Core namespace declaration: |
DCMI Metadata Terms | proposed | |
| DCTERMS.hasPart | External Resource | Not allowed | A related resource that is included either physically or logically in the described resource. Requires Dublin Core namespace declaration: |
DCMI Metadata Terms | proposed | |
| DCTERMS.hasVersion | External Resource | Not allowed | A related resource that is a version, edition, or adaptation of the described resource. Requires Dublin Core namespace declaration: |
DCMI Metadata Terms | proposed | |
| DCTERMS.isFormatOf | External Resource | Not allowed | A related resource that is substantially the same as the described resource, but in another format. Requires Dublin Core namespace declaration: |
DCMI Metadata Terms | proposed | |
| DCTERMS.isPartOf | External Resource | Not allowed | A related resource in which the described resource is physically or logically included. Requires Dublin Core namespace declaration: |
DCMI Metadata Terms | proposed | |
| DCTERMS.isReferencedBy | External Resource | Not allowed | A related resource that references, cites, or otherwise points to the described resource. Requires Dublin Core namespace declaration: |
DCMI Metadata Terms | proposed | |
| DCTERMS.isReplacedBy | External Resource | Not allowed | A related resource that supplants, displaces, or supersedes the described resource. Requires Dublin Core namespace declaration: |
DCMI Metadata Terms | proposed | |
| DCTERMS.isRequiredBy | External Resource | Not allowed | A related resource that requires the described resource to support its function, delivery, or coherence. Requires Dublin Core namespace declaration: |
DCMI Metadata Terms | proposed | |
| DCTERMS.isVersionOf | External Resource | Not allowed | A related resource of which the described resource is a version, edition, or adaptation. Changes in version imply substantive changes in content rather than differences in format. Requires Dublin Core namespace declaration: |
DCMI Metadata Terms | proposed | |
| DCTERMS.license | External Resource | Not allowed | A legal document giving official permission to do something with the resource. Requires Dublin Core namespace declaration: |
DCMI Metadata Terms | It may be replaced by the literal value in form of <meta name="DCTERMS.license" content="..." />
|
proposed |
| DCTERMS.mediator | External Resource | Not allowed | An entity that mediates access to the resource and for whom the resource is intended or useful. In an educational context, a mediator might be a parent, teacher, teaching assistant, or care-giver. Requires Dublin Core namespace declaration: |
DCMI Metadata Terms | It may be replaced by the literal value in form of <meta name="DCTERMS.mediator" content="..." />
|
proposed |
| DCTERMS.publisher | External Resource | Not allowed | An entity responsible for making the resource available. Examples include a person, an organization, or a service. Requires Dublin Core namespace declaration: |
DCMI Metadata Terms | It may be replaced by the literal value in form of <meta name="DCTERMS.publisher" content="..." />
|
proposed |
| DCTERMS.references | External Resource | Not allowed | A related resource that is referenced, cited, or otherwise pointed to by the described resource. Requires Dublin Core namespace declaration: |
DCMI Metadata Terms | proposed | |
| DCTERMS.relation | External Resource | Not allowed | A related resource. Requires Dublin Core namespace declaration: |
DCMI Metadata Terms | proposed | |
| DCTERMS.replaces | External Resource | Not allowed | A related resource that is supplanted, displaced, or superseded by the described resource. Requires Dublin Core namespace declaration: |
DCMI Metadata Terms | proposed | |
| DCTERMS.requires | External Resource | Not allowed | A related resource that is required by the described resource to support its function, delivery, or coherence. Requires Dublin Core namespace declaration: |
DCMI Metadata Terms | proposed | |
| DCTERMS.rightsHolder | External Resource | Not allowed | A person or organization owning or managing rights over the resource. |