Revision as of 13:30, 15 October 2007

existing rel values

This page contains tables of known 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.

formats

These rel values are defined formats from specifications (HTML 4, microformats) are thus are recommended for general use. Alphabetically ordered by value.

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.

Sources:

W3C HTML 4 link type and GRDDL spec
xfn and other microformats


rel value	summary (from the relevant specification where possible))	defining specification
acquaintance	the person represented by the current document considers the person represented by the referenced document to be an acquaintance	XFN
alternate	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 type
appendix	Refers to a document serving as an appendix in a collection of documents.	HTML4 link type
bookmark	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 type
chapter	Refers to a document serving as a chapter in a collection of documents.	HTML4 link type
child	the referenced person is a child of the person represented by the current document	XFN
colleague	the referenced person is a colleague of the person represented by the current document	XFN
contact	the person represented by the current document considers the person represented by the referenced document to be a contact	XFN
contents	Refers to a document serving as a table of contents. Some user agents also support the synonym ToC (from "Table of Contents").	HTML4 link type
copyright	Refers to a copyright statement for the current document.	HTML4 link type
co-resident	the referenced person lives in the same residence as the person represented by the current document	XFN
co-worker	the referenced person is a co-worker of the person represented by the current document	XFN
crush	this person considers the referenced person to be a crush (i.e. has a crush on the referenced person)	XFN
date	this person considers the referenced person to be a date (i.e. is dating the referenced person)	XFN
friend	the person represented by the current document considers the person represented by the referenced document to be a friend	XFN
glossary	Refers to a document providing a glossary of terms that pertain to the current document.	HTML4 link type
help	Refers to a document offering help (more information, links to other sources information, etc.)	HTML4 link type
index	Refers to a document providing an index for the current document.	HTML4 link type
kin	the referenced person is part of the extended family of the person represented by the current document	XFN
license	…indicates that the [referenced document] is a license for the current page.	rel-license
me	the referenced document represents the same person as does the current document	XFN
met	this person has met the referenced person	XFN
muse	the referenced person inspires the person represented by the current document	XFN
neighbor	the referenced person lives nearby the person represented by the current document	XFN
next	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 type
nofollow	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	the referenced person is a parent of the person represented by the current document	XFN
prev	Refers to the previous document in an ordered series of documents. Some user agents also support the synonym "Previous".	HTML4 link type
previous	Synonym of `prev`	HTML4 link type
section	Refers to a document serving as a section in a collection of documents.	HTML4 link type
sibling	the referenced person is a sibling of the person represented by the current document	XFN
spouse	the referenced person is a spouse of the person represented by the current document	XFN
start	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 type
stylesheet	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 type
subsection	Refers to a document serving as a subsection in a collection of documents.	HTML4 link type
sweetheart	this person considers the referenced person to be their sweetheart	XFN
tag	…indicates that the [referenced document] is an author-designated "tag" (or keyword/subject) for the current page.	rel-tag
toc	Synonym of `contents` (from "Table Of Contents")	HTML4 link type
transformation	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 spec

notes

rel="alternate" can take further meaning from additional attributes, such as
- rel="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
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
home	…indicates that the [referenced document] is the homepage of the site in which the current page appears.	rel-home
payment	…	rel-payment

brainstorming

Several rel values are being brainstormed as potential microformats and are thus listed here. If you find you have a use for such semantics in real world examples, consider trying out these values and provide feedback on the respective brainstorming page(s) with your results and experiences.


rel value	summary	brainstormed in
bibliography	indicate[s] that the destination of that hyperlink is a bibliography for the current page.	mailing list post, 2007-10-15
cite	indicate[s] that the destination of that hyperlink is an authoritative source or a precedent to the current page.	distributed-conversation-brainstorming
group	the referenced document represents a group to which the person represented by the current document belongs	group-brainstorming
member	the referenced document represents a member of the group represented by the current document	group-brainstorming
product	…	product-brainstorming
profile	…	xmdp-brainstorming
(various)	XFN values for family relationships	genealogy-brainstorming#Relationships

POSH usage

There are numerous rel values used as POSH, both in the wild, whose origins are not necessarily known, nor are their meanings consistent. There are also numerous rel values from external proposals of varying degrees of merit. It is useful to document their existence and summarize their implied meanings/usage intent as research that may be used to perhaps take one or more of them thru the microformats process if there is both sufficient interest and sufficient in the wild usage.

Note: this list is incomplete, please help complete it from the following sources:

External sources:

Meta Information in DevMo Docs (DevMo)
Microsummary
Web Communication Link Relationships (WCLR)
W3C Link Relationship values draft (LRdraft) - from a draft of the HTML spec circa 1991.
HTML5 draft Liable to change


rel value	summary	origin	proposal(s)
archive	index of archived entries	unknown, perhaps Wordpress open source blogging software	WCLR
archives	Provides a link to a collection of records, documents, or other materials of historical interest.		HTML5
author	…	unknown	DevMo
comment	…	…	WCLR
contribution	…	…	WCLR
details	…	(seen on w3c.org news log in a "read more" permalink)	…
EditURI	…	Seen in WordPress, e.g. [1]	…
endorsed	…	…	WCLR
external	Indicates that the referenced document is not part of the same site as the current document.	…	HTML5
feed	Gives the address of a syndication feed for the current document.	…	WCLR/ HTML5
icon	Imports an icon to represent the current document. (Allowed in `link` only)	…	WCLR/ HTML5
lightbox	…	(Google search for rel=lightbox in the wild)	…
made	…	…	LRdraft
meta	…	(seen on w3c.org - citation needed)	…
microsummary	…	…	Microsummary, be aware of: microsummary issues
openid.delegate	…	(Google search for rel=openid.* in the wild)	…
openid.server	…	(Google search for rel=openid.* in the wild)	…
permalink	…	…	WCLR
pgpkey	(see also rel-publickey)	…	[2], [3]
pingback	Gives the address of the pingback server that handles pingbacks to the current document. (Allowed in `link` only)	…	WCLR/ HTML5
prefetch	Specifies that the target resource should be pre-emptively cached. (Allowed in `link` only)	…	HTML5
publickey	(see also rel-pgpkey)	…	[4]
referral	…	…	WCLR
related	…	…	WCLR
resource	…	…	WCLR
search	…	unknown	unknown
sidebar	Specifies that the referenced document, if retrieved, is intended to be shown in the browser's sidebar (if it has one).		HTML5
sponsor	…	…	WCLR
trackback	…	unknown, perhaps open source Movable Type blogging software	WCLR
unendorsed	(probably redundant to nofollow)	…	WCLR
up	Provides a link to a document giving the context for the current document.	…	HTML5
user	…	…	WCLR
via	…	…	WCLR

WCLR

The WCLR proposal is described by its author (in e-mail, 2007-09-25) as:

…now effectively obsolete, since HTML5 and Microformats cover all the worthwhile relationships in that already.
These are covered by HTML5 already:

permalink -> bookmark

archive -> archives

feed

pingback

unendorsed -> nofollow

The rest now seem unnecessary.

Nonetheless, there may be some mileage in using them in microformats, at least until HTML5 is widely available.

dropped

The following rel values were in earlier version(s) of specification(s) and it is presumed by their absence from the most recent version of the respective specification(s) that they have been deprecated or obsoleted. Use of them could be considered a bit more standard than just POSH, although you may wish to research why such values were omitted from latter specifications before using them. If you do discover the reasoning, please add a short statement or link to thereof into the appropriate place in the following table.

Sources: HTML3 (expired!) - (has been superceded by HTML 3.2 - which itself has been superceded by HTML 4.0 - which itself has been updated by HTML 4.01, commonly referred to as "HTML 4" in this wiki and other places.)


rel value	summary	defining specification	why dropped
banner	Was used to reference another document to be used as banner for this document (i.e. a form of "include" statement).	HTML 3	unknown
up	When the document forms part of a hierarchy, this link references the immediate parent of the current document.	HTML 3	unknown, but proposed for re-introduction in HTML5

rejected

Some rel values have been proposed and rejected. These are not recommended for use, and listed here to make that explicit.

Source: rejected-formats.


rel value	origin / proposal	why rejected
pavatar	pavatar	rejected-formats#Pavatar

unspecified

Some rel values have been added to this page perhaps in one of the tables above, but no examples, nor an actual specification explicitly stating that the value(s) should be used in the HTML4 'rel' attribute could be found. They are listed here in the hopes someone can discover more specific/precise URLs to examples or specifications about them (preferably both). Until such precise URLs to examples/specs are provided, the values can be treated as they are purely theoretical and thus of little interest.


rel value	summary	possible source
schema.DC	…	Dublin Core
schema.DCTERMS	…	Dublin Core

Notes:

Dublin Core. This search may help: [5]. At first glance it appears the results from the search show only uses 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 Dublin Core in user visible content like <a href> appears to be strictly theoretical.
http://www.ietf.org/rfc/rfc2731.txt - also has rel="schema.AC" and rel="schema.RC" with the pattern rel="schema.PREFIX".

tools

See implementations.

@@ Line 4: / Line 4: @@
 This page contains tables of known 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.
-Note: these lists may be incompleete, please help complete them from the referenced sources.
+<span id="usage">usage</span>: see [[rel-faq#How_is_rel_used|how is 'rel' used]].  Regarding <span id="rev">rev</span>, see: [[rel-faq#Should_rev_even_be_used|should 'rev' even be used]].
-== usage ==
-See [[rel-faq#How_is_rel_used]].  Regarding <span id="rev">rev</span>, see: [[rel-faq#Should_rev_even_be_used]].
 == formats ==
 These rel values are defined formats from specifications (HTML 4, microformats) are thus are <strong>recommended for general use</strong>.  Alphabetically ordered by value.
+<strong>Do not</strong> add rel values you find in the wild to this table of rel formats, instead add them to the table in the [[existing-rel-values#POSH_usage|POSH section]].
 Sources:
-* [http://www.w3.org/TR/html401/types.html#h-6.12 HTML 4 link type]
+* W3C [http://www.w3.org/TR/html401/types.html#h-6.12 HTML 4 link type] and [http://www.w3.org/TR/grddl/ GRDDL spec]
 * [[xfn]] and other [[microformats]]
@@ Line 61: / Line 60: @@
 |-
 | [[rel-date|date]] || this person considers the referenced person to be a date (i.e. is dating the referenced person)|| [[XFN]]
-|-
-| [[rel-details|details]] || (seen on w3c.org news log in a "read more" permalink) || ???
 |-
@@ Line 73: / Line 69: @@
 |-
 | [[rel-help|help]] || Refers to a document offering help (more information, links to other sources information, etc.) || [http://www.w3.org/TR/html4/types.html#h-6.12 HTML4 link type]
-|-
-| [[rel-home|home]] || &hellip;indicates that the <nowiki>[referenced document]</nowiki> is the homepage of the site in which the current page appears. || [[rel-home]]
 |-
@@ Line 85: / Line 78: @@
 |-
 | [[rel-license|license]] || &hellip;indicates that the <nowiki>[referenced document]</nowiki> is a license for the current page. || [[rel-license]]
-|-
-| [[rel-lightbox|lightbox]] || ??? ([http://www.google.co.uk/search?q=rel%3D%22lightbox%22 rel=lightbox in the wild]) || ???
 |-
@@ Line 94: / Line 84: @@
 |-
 | [[rel-met|met]] || this person has met the referenced person || [[XFN]]
-|-
-| [[rel-meta|meta]] || (seen on w3c.org) || ???
 |-
@@ Line 108: / Line 95: @@
 |-
-| [[rel-nofollow|nofollow]] || &hellip;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]]
+| [[rel-nofollow|nofollow]] || 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]]
-|-
-| openid.delegate || See below. ([http://www.google.co.uk/search?q=%22rel%3Dopenid%22 rel=openid.* in the wild]) || ???
-|-
-| openid.server || See above. ([http://www.google.co.uk/search?q=%22rel%3Dopenid%22 rel=openid.* in the wild]) || ???
 |-
@@ Line 147: / Line 128: @@
 |-
-| [[rel-transformation|transformation]] || 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]]) || [http://www.w3.org/2003/g/data-view#transformation GRDDL spec]
+|[[rel-tag|tag]] || &hellip;indicates that the <nowiki>[referenced document]</nowiki> is an author-designated "tag" (or keyword/subject) for the current page. || [[rel-tag]]
 |-
-|[[rel-tag|tag]] || &hellip;indicates that the <nowiki>[referenced document]</nowiki> is an author-designated "tag" (or keyword/subject) for the current page. || [[rel-tag]]
+|[[rel-toc|toc]] || Synonym of <code>contents</code> (from "Table Of Contents") || [http://www.w3.org/TR/html4/types.html#h-6.12 HTML4 link type]
 |-
-|[[rel-toc|toc]] || Synonym of <code>contents</code> (from "Table Of Contents") || [http://www.w3.org/TR/html4/types.html#h-6.12 HTML4 link type]
+| [[rel-transformation|transformation]] || 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]] || [http://www.w3.org/TR/grddl/#transformation GRDDL spec]
 |-
 |}
@@ Line 174: / Line 157: @@
 |-
 | [[rel-enclosure|enclosure]] || &hellip;indicates that the destination of that hyperlink is intended to be downloaded and cached. || [[rel-enclosure]]
+|-
+| [[rel-home|home]] || &hellip;indicates that the <nowiki>[referenced document]</nowiki> is the homepage of the site in which the current page appears. || [[rel-home]]
 |-
 | [[rel-payment|payment]] || &hellip; || [[rel-payment]]
@@ Line 187: / Line 172: @@
 |-
-| [[rel-bibliography|bibliography]] || indicate[s] that the destination of that hyperlink is a bibliography for the current page. || [http://microformats.org/discuss/mail/microformats-discuss/2007-October/010863.html mailing list post, 2007-10-15]]
+| [[rel-bibliography|bibliography]] || indicate[s] that the destination of that hyperlink is a bibliography for the current page. || [http://microformats.org/discuss/mail/microformats-discuss/2007-October/010863.html mailing list post, 2007-10-15]
 |-
@@ Line 239: / Line 224: @@
 |-
 | [[rel-contribution|contribution]] || &hellip; || &hellip; || WCLR
+|-
+| [[rel-details|details]] || &hellip; || (seen on w3c.org news log in a "read more" permalink) || &hellip;
 |-
@@ Line 254: / Line 242: @@
 |-
 | [[rel-icon|icon]] || Imports an icon to represent the current document. (Allowed in <code>link</code> only) || &hellip; || WCLR/ HTML5
+|-
+| [[rel-lightbox|lightbox]] || &hellip; || ([http://www.google.co.uk/search?q=rel%3D%22lightbox%22 Google search for rel=lightbox in the wild]) || &hellip;
 |-
 | [[rel-made|made]] || &hellip; || &hellip; || LRdraft
+|-
+| [[rel-meta|meta]] || &hellip; ||  (seen on w3c.org - citation needed) || &hellip;
 |-
 | [[rel-microsummary|microsummary]]|| &hellip; || &hellip; ||[http://wiki.mozilla.org/Microsummaries Microsummary], be aware of: [[page-summary-formats#Issues_2|microsummary issues]]
+|-
+| [[rel-openid-delegate|openid.delegate]] || &hellip; || ([http://www.google.co.uk/search?q=%22rel%3Dopenid%22 Google search for rel=openid.* in the wild]) || &hellip;
+|-
+| [[rel-openid-server|openid.server]] || &hellip; || ([http://www.google.co.uk/search?q=%22rel%3Dopenid%22 Google search for rel=openid.* in the wild]) || &hellip;
 |-

existing-rel-values: Difference between revisions

Revision as of 13:30, 15 October 2007

existing rel values

Contents

formats

notes

proposals

brainstorming

POSH usage

WCLR

dropped

rejected

unspecified

tools

related

Navigation menu

existing-rel-values: Difference between revisions

Revision as of 13:30, 15 October 2007

existing rel values

formats

notes

proposals

brainstorming

POSH usage

WCLR

dropped

rejected

unspecified

tools

related

Navigation menu

Search