Microformats Wiki - User contributions [en]

xfolk

2008-07-12T15:39:17Z

WalterJJ: /* In the wild */

<h1> xFolk (RC1) </h1>

'''xFolk''' (from "xFolksomony") is a simple and open format for publishing collections of bookmarks. It better enables services for improving user experience and sharing data in web-based bookmarking software. xFolk may be embedded in HTML or XHTML, Atom, RSS, and arbitrary XML. It is one of several open [[microformats|microformat]] standards.

__TOC__

== Draft Specification ==

=== Editor/Author ===
[http://thecommunityengine.com/ Bud Gibson] ([http://thecommunityengine.com The Community Engine])

=== Copyright ===
{{MicroFormatCopyrightStatement2005}}

=== Patents ===
{{MicroFormatPatentStatement}}

=== Inspiration and Acknowledgments ===
Thanks to: [http://www.cnbc.cmu.edu/~plaut/ David Plaut] who introduced me to the idea that items may partially belong to many categories at once. More recently, thanks to: [http://tantek.com/ Tantek Çelik], [http://epeus.blogspot.com/ Kevin Marks], [http://steve.osdir.com/ Steve Mallet], [http://hybernaut.com/ Brian DelVecchio], and [http://blogmarks.net François Hodierne] who have contributed to the development of xFolk with thoughtful critiques and implementations.

== Introduction ==
Social bookmarking services let users save and tag bookmarks to share with other users. Over the past year, the number of these services has mushroomed to [http://en.wikipedia.org/wiki/Social_bookmarking over 20], with popular examples including: [http://del.icio.us del.icio.us], [http://furl.net furl], [http://de.lirio.us de.lirio.us], [http://jots.com jots], and [http://blogmarks.net blogmarks].

Lack of an open, interoperable data standard is a major issue in using social bookmarking services. An open standard would make it possible to easily collect social bookmark data and remix it to invent new services along the lines of [http://gataga.com gataga]'s experimental bookmark search engine. An open standard would also make it possible to write javascripts that work across services [http://johnvey.com/features/deliciousdirector/ as some currently do for del.icio.us], enabling across-the-board improvements in user experience.

xFolk is an open social bookmarking standard that aims to achieve both benefits. Social bookmarking services that adopt xFolk will continue to differentiate themselves with data services. But, the data itself will be easy to manipulate by third party scripts and easy to share. As a result, bookmarking services will be able to offer a wider array of options to their users at low cost and focus on what truly differentiates them. Individuals or groups operating standalone bookmark repositories will have access to a wider array of functionality than they can produce on their own.

== Semantic XHTML Design Principles ==
{{semantic-xhtml-design-principles}}

== Format ==
Extensive analysis of social bookmarking services and linkblogs, reported on [http://thecommunityengine.com/home/archives/xfolk elsewhere], reveals that the data published by both bookmarking services and '''many''' different linkblogs are described by the following implied schema:

* A bookmarked or tagged link.
* A title for the entry.
* Tags for the link.
* An extended description or summary of the link.

As demonstrated in early iterations of the xFolk standard, this general schema can be translated into markup by:

# creating a container element for each entry of class <code>xfolkentry</code>,
# using an <a> element for the bookmarked or tagged link of class <code>taggedlink</code>,
# using title attribute for the tagged link <a> element, if it exists, as the entry title, otherwise using the element value,
# using [[rel-tag]] for the tags, and
# using a container element of class <code>description</code>, such as <p>, for any extended description or summary.

A given xFolk entry will always contain a tagged link including a title with all other elements optional. Entries may have more than one tag as well as more than one element of class <code>description</code>. Multiple elements of class <code>description</code> are ordered by default document order. Semantic elements within xFolk entries may be nested at arbitray depths.

Many social bookmarking systems exist, each with its own markup conventions. Further, many people are already publishing personal link blogs. xFolk is designed with ease of adapting to these current practices as a primary goal. Therefore, few assumptions are made as to the exact kinds of elements used for an xFolk entry. Rather, the work of defining semantics is left entirely to the class and rel (in the case of [[rel-tag]]) attribute values.

It is expected that developers will use [http://www.w3.org/TR/xpath XPath] or equivalent syntax in accessing xFolk entry elements. a requirement for XPath is that the HTML document be well-formed but not necessarily valid. Thus, while not optimal, it is possible to serviceably use xFolk in an HTML document that does not validate.

=== XMDP Profile ===

See the [[xfolk-profile|xFolk profile]] for the [http://gmpg.org/xmdp XMDP] profile of xFolk.

== Example ==
Here is a sample bookmark as displayed in [http://del.icio.us del.icio.us]'s standard markup. Lines where the value of elements' class attributes must change to conform to xFolk are marked with a comment at the end.
<pre><div class="post"> 
<div>
<a class="delLink" href="http://www.sifry.com/alerts/archives/000306.html"> 
Sifry's Alerts: Technorati launches Related Tags
</a>
</div>
<div class="extended"> 
Ever wanted to see what posts are related to other posts, what tags
are related to others? Now you can! Just check under the Tag
description on most tag pages, like this one, or this one, and you'll
see the patterns. Can you smell the emergence?
</div>
<div class="meta">
to
<a class="delNav" href="/fpgibson/folksonomy">folksonomy</a> 
<a class="delNav" href="/fpgibson/technorati">technorati</a> 
... <a class="delNav" href="/url/cbcabf7de070fdb46598ee679367be49">
and 1 other person
</a>
... on 2005-04-09
</div>
</div></pre>

The equivalent in xFolk is as follows. Comments are placed at the end of lines where class attribute changes were required.
<pre><nowiki>
<div class="xfolkentry"> 
<div>
<a class="taggedlink" href="http://www.sifry.com/alerts/archives/000306.html"> 
Sifry's Alerts: Technorati launches Related Tags
</a>
</div>
<div class="description"> 
Ever wanted to see what posts are related to other posts, what tags
are related to others? Now you can! Just check under the Tag
description on most tag pages, like this one, or this one, and you'll
see the patterns. Can you smell the emergence?
</div>
<div class="meta">
to
<a rel="tag" href="/fpgibson/folksonomy">folksonomy</a> 
<a rel="tag" href="/fpgibson/technorati">technorati</a> 
... <a class="delNav" href="/url/cbcabf7de070fdb46598ee679367be49">
and 1 other person
</a>
... on 2005-04-09
</div>
</div>
</nowiki></pre>

Converting markup to be conformant with xFolk is almost always this easy. The advantage of xFolk is that it provides one set of class attributes that can be reused across all services and link blogs, almost always with no loss of granularity. The next section presents several more examples to illustrate this point.

Another simple example (using lists markup) :
<pre>
<nowiki>
<ul>
<li>
<ul class="xfolkentry">
<li><a class="taggedlink" href="http://microformats.org/wiki/Main_Page">microformats wiki</a></li>
<li class="description">The main place for understanding microformats and playing with...</li>
<li class="description">Community driven wiki</li>
<li class="meta">
Tags :
<a rel="tag" href="http://del.icio.us/tag/microformats">microformats</a>
<a rel="tag" href="http://del.icio.us/tag/websocial">websocial</a>
<a rel="tag" href="http://del.icio.us/tag/semantics">semantics</a>
</li>
</ul>
</li>

<li>

</li>

</ul>
</nowiki>
</pre>

== Many more examples ==

We have numerous examples to help developers incorporate xFolk into their sites.

=== In the wild ===

These are real live examples of functioning systems that publish bookmarks in xFolk. These are a great place to start for anyone looking for examples "in the wild" to try parsing, indexing, organizing etc. If you publish using xFolk, feel free to add it to the top of this list. Once the list grows too big, we'll make a separate wiki page.

* [http://www.idoneos.com Idoneos.com] , a conceptually networked collection of information pages (mostly spanish), is tagging bookmarks with xFolk.
* [http://ashaszin.lautre.net/ Ashaszin] - Small blog running with [http://spip.net SPIP] : del.icio.us links and web feeds tagged with xFolk .
* [http://www.rolandinsh.lv/blog/ Rolands Umbrovskis - blog] all blog posts are marked up with xFolk.
* [http://www.bbc.co.uk/worldservice/bangladeshboat BBC World Service Bangladesh River Journey] a social network mashup, uses basic xFolk for bookmarking hAtom entries. See [http://dharmafly.com/blog/bangladeshboat Dharmafly blog discussion].
* [http://waferbaby.com/hussy waferbaby's Hussy] currently publishes links using xFolk.
* [http://smarking.com/ Smarking] currently publishes all shared links (including search results) using xFolk.
* [http://unalog.com unalog] currently publishes all shared links (including search results) using xFolk.
* [http://de.lirio.us de.lirio.us] currently publishes its bookmarks using xFolk (with the deprecated class attribute <code>extended</code> in place of <code>description</code>, see [[xfolk-profile | the XMDP]]).
* [http://dev.blogmarks.net/wiki/BlogSync blogmarks] currently exports bookmarks to blogs in xFolk (scroll down to the export example on the page; the deprecated class attribute <code>extended</code> is used in place of <code>description</code>, see [[xfolk-profile | the XMDP]]).
* [http://thecommunityengine.com The Community Engine] uses xFolk (with the deprecated class attribute <code>extended</code> in place of <code>description</code>, see [[xfolk-profile | the XMDP]]) for its [http://thecommunityengine.com/home main entries] and for its [http://thecommunityengine.com/webcites republished bookmarks].
* [http://groovymother.com/links/ Groovy Links] is a link blog which is marked up with xFolk.
* [http://tommorris.org/blog/ Tom Morris] - daily del.icio.us links are marked up with xFolk, [[hCard]] and [[vote-links]].

=== Additional social bookmarking services ===

This example illustrates how xFolk may be applied to one additional service:

* [[xfolk-scuttle | scuttle]]

=== Link blogs ===

Social bookmarking services are only the most recent examples of people publishing links. Link blogs have been around almost since the beginning of blogging. They represent somewhat more of a challenge for xFolk because their markup tends to be less semantic from the outset. The following examples illustrate some particular challenges and how they can be overcome.

* [[xfolk-kottke | kottke]]
* [[xfolk-pollas | pollas]]
* [[xfolk-jacobian | jacobian]]
* [[xfolk-julian-bez | julian-bez]]

=== Spam ===
Some spammers are adding xFolk tags to their link farms. (It's probably a bad idea to actually link to these sites.) For example,
* phontron.info

== Implementations ==

The following implementations have been developed which generate or use xFolk. If you have an xFolk implementation, feel free to add it to the top of this list. Once the list grows too big, we'll make a separate wiki page.

* [http://buzka.com Buzka], a social bookmarking service, now supports xFolk
* [http://blip.tv Blip.tv], a video hosting site, now [http://blog.blip.tv/blog/2006/08/19/blip-supports-xfolk/ supports xFolk].
* [http://www.s9y.org/ Serendipity], a PHP-powered, flexible Blogging/CMS application, now has a [http://www.numblog.de/archives/241-Social-Bookmarks-Plugin-for-Serendipity.html social bookmarks plugin] that supports xFolk.
* [http://claimid.com claimID] has implemented xFolk for people's links.
* [http://ma.gnolia.com ma.gnolia] now supports xFolk.
* [http://smarking.com/ Smarking.com] (a social bookmarking service) marks up their tagged links with xFolk! Hat tip: [http://3spots.blogspot.com/2006/05/social-bookmarking-smarking.html 3spots: Social + bookMARKING = Smarking] which itself is an [[hreview|hReview]].
* [http://blog.codeeg.com/2006/03/20/flock-tails-flocktails/ Flocktails] - port of Tails extension for Flock 0.5.12 that looks for hCards, hCalendar, xFolk and hReview and tosses them into a handy topbar
* [http://blog.codeeg.com/tails-firefox-extension/ Tails is a Firefox Extension] that will display the presence of microformats ([[hcard|hCard]], [[hcalendar|hCalendar]], [[hreview|hReview]], [[xfolk|xFolk]]) on a webpage.
* Bud Gibson and Mike Migurski [http://thecommunityengine.com/home/archives/2005/09/vegomatic_an_al.html have written] [http://thecommunityengine.com/veg-o-matic veg-o-matic], an xFolk reblogging tool and service.
* [http://inside.glnetworks.de/ Martin Rehfeld] has updated the work of [http://blogmatrix.blogmatrix.com/ David Janes] and produced a [[Greasemonkey]] [http://inside.glnetworks.de/2006/06/05/microformats-have-arrived-in-firefox-15-greasemonkey-06/ script] that finds many microformat elements, including xFolk and [http://blog.davidjanes.com/mtarchives/2005_08.html#003379 provides a popup menu of actions]. ''This will work with FireFox 1.5+/GreaseMonkey 0.6.4+ now.''
* [http://www.midgard-project.org/midcom-permalink-6416db7e1f0e297b4cf3dcc285702a8d net.nemein.bookmarks], the bookmark manager in [http://www.midgard-project.org/ Midgard CMS] uses xFolk as the native output format, with added <code>abbr class=posted</code> for publication date and <code>abbr class=poster</code> for user who added the bookmark. See [http://bergie.iki.fi/links/ example]
* [http://de.lirio.us de.lirio.us] currently publishes its bookmarks using xFolk 0.4 (the class attribute <code>extended</code> is used in place of description).
* [http://dev.blogmarks.net/wiki/BlogSync blogmarks] currently exports bookmarks to blogs in xFolk 0.4 (scroll down to the export example on the page; the class attribute <code>extended</code> is used in place of <code>description</code>).
* [http://pokkari.com/microformat/javadoc/ Sivitols] is a Java library for microformats. Currently only the xFolk RC1 standard is implemented, but additional microformat support is planned. (adapted from [http://blog.blip.tv/blog/microformats/])
* [http://bildu.net Bildu] a social bookmarking service in Basque that supports xFolk (an also rel-tag).
* [http://bookmarks.excite.co.uk/ Excite Bookmarks] a social bookmarking service that supports xFolk and rel-tag.

== References ==
=== Normative References ===
* [http://www.w3.org/TR/2002/REC-xhtml1-20020801/ XHTML 1.0 SE]
* [[rel-tag]]

=== Informative References ===
* [http://thecommunityengine.com/home/archives/xfolk articles about xFolk]
* [http://thecommunityengine.com/home/archives/tags/microformats articles about the business value of microformats]
* [http://gataga.com gataga social bookmark search engine]
* [http://johnvey.com/features/deliciousdirector/ an ajax based interface for del.icio.us]
* [http://en.wikipedia.org/wiki/Social_bookmarking social bookmarking defined at wikipedia]

=== Similar Work ===
* [[hreview | hReview]]

== Work in progress ==
Although this specification has recently begun to stabilize as indicated by the version RC1, it is still a work in progress. If warranted, I am prepared to go through multiple release candidates to achieve the narrow purpose of making bookmark entries more genrally accessible with as with as light weight a format as possible. All changes since the last iteration have been motivated by the implementation experience of developers attempting to achieve this narrow aim. Further changes will also most likely be motivated by implementation concerns. See "future directions" below for additional microformat possibilities.

=== Changes since xFolk 0.4 ===
The class attribute value <code>extended</code> was deprecated in favor <code>description</code> to better conform with other microformat usage and some requests during implementation. The other change has been to allow use of multiple elements of class <code>extended</code> based on some use cases discovered in implementation.

=== Future directions ===
There are several extensions one might imagine for xFolk. Frequently, these extensions are best achieved by combining xFolk with another microformat. For instance, one might want to indicate his or her evaluation of the bookmarked item. This might be achieved by using [[vote-links | Vote Links]] or [[hreview | hReview]] with xFolk.

One can also imagine extending xFolk to provide data conformant with various social bookmarking service APIs, for instance to provide all bookmarks by tag. These APIs are currently too fluid for specification in any kind of standard. The APIs and the functionality they provide represent one way social bookmarking services and meta services can differentiate themselves.

A companion format called "xFolk definition" is under development. xFolk definition will provide a means of explicitly defining the tags used in social bookmarks.

=== Brainstorming ===
* [[xfolk-brainstorming|xFolk brainstorming]]

== Discussions ==

=== Q&A ===
* If you have any questions about xFolk, check the [[xfolk-faq|xFolk FAQ]], and if you don't find answers, add your questions!

=== Issues ===
* Please add any issues with the specification to the separate [[xfolk-issues|xFolk issues]] document.

==Related pages==
{{template:xfolk-related-pages}}

rel-tag

2008-07-12T15:27:40Z

WalterJJ: /* Examples in the Wild */

<h1> rel-tag </h1>

__TOC__

== Draft Specification 2005-01-10 ==
; Editors/Authors
:[http://tantek.com/ Tantek Çelik]
:[http://epeus.blogspot.com/ Kevin Marks]

;Concept
:[http://powazek.com/ Derek Powazek]

=== Copyright ===
{{MicroFormatCopyrightStatement2004}}
* [[User:Tantek|Tantek]]: I release all my contributions to this specification into the public domain and I encourage the other authors to do so as well.
** When all authors/editors have done so, we can remove the MicroFormatCopyrightStatement template reference and replace it with the MicroFormatPublicDomainContributionStatement.

=== Patents ===
{{MicroFormatPatentStatement}}

== Abstract ==
[[Rel-Tag]] is one of several [[MicroFormats]]. By adding <code>rel="tag"</code> to a hyperlink, a page indicates that the destination of that hyperlink is an author-designated "tag" (or keyword/subject) for the current page. Note that a tag may just refer to a major portion of the current page (i.e. a blog post). e.g. by placing this link on a page,

<pre><nowiki><a href="http://technorati.com/tag/tech" rel="tag">tech</a></nowiki></pre>

the author indicates that the page (or some portion of the page) has the tag "tech".

The linked page SHOULD exist, and it is the linked page, rather than the link text, that defines the tag. The last path component of the URL
is the text of the tag, so

<pre><nowiki><a href="http://technorati.com/tag/tech" rel="tag">fish</a></nowiki></pre>

would indicate the tag "tech" rather than "fish".

== Scope ==
rel="tag" is specifically designed for "tagging" content, typically web pages (or portions thereof, like blog posts).

rel="tag" is NOT designed for "tagging" arbitrary URLs or external content. There is demand for a general decentralized syntax for tagging URLs external to the current page, but this is not meant for that. See [[xfolk|xFolk]] and [[hreview|hReview]] for ways to tag arbitrary URLs.

If you need to define tags as part of a more specialized format, rel="tag" is the recommended way to do so, and [[xfolk|xFolk]], [[hreview|hReview]], [[hcard |hCard]] and [[hcalendar|hCalendar]] all do this.
== XMDP profile ==
<pre><nowiki>
<dl class="profile">
<dt id="rel">rel</dt>
<dd><p>
<a rel="help" href="http://www.w3.org/TR/html401/struct/links.html#adef-rel">
HTML4 definition of the 'rel' attribute.</a>
Here is an additional value.</p>
<dl>
<dt id="tag">tag</dt>
<dd>Indicates that the referred resource serves as a "tag",
or keyword/subject, for the referring page.</dd>
</dl>
</dd>
</dl>
</nowiki></pre>

== Tag Spaces ==

Tags are embedded in HTTP URIs in a well-defined manner so that the tag embedded in an HTTP URI can be mechanically extracted from that URI. Specifically, the last segment of the path portion of the URI (after the final "/" character) contains the tag value. For example, the URI <pre><nowiki>http://www.example.com/tags/foo</nowiki></pre> contains the tag "foo".

Thus, for the purposes of comparing two HTTP URIs as tags, the last segment of the path portion should be extracted and only that value (that value of the tag) should be compared.

''Need more formal language about comparison and extraction process.''

The destination of a rel="tag" hyperlink is required to be a tag space (a place that collates or defines tags), where the last segment of the path of the URL is the tag, e.g.

<pre><nowiki>http://technorati.com/tag/tech </nowiki></pre>

is a URL for the tag "tech".

Tags may only be placed in the URL path, and only in the last segment of the path. Tags may not be placed in query parameters or fragment identifiers. e.g.

<pre><nowiki>http://technorati.com/tag/tech?tag=fish#emu </nowiki></pre>

is still a URL for the tag "tech", not "fish" or "emu".

Since the only part of a tag space URL of which any structure is required is the last path segment, a tag space URL can be hosted at any domain. Authors may choose to link to a tag at a particular tag space in order to provide a specific meaning. E.g. a tag for technology could link to:

<pre><nowiki> http://en.wikipedia.org/wiki/Technology </nowiki></pre>

Trailing slashes in tag URLs are ignored, that is:

<pre><nowiki> http://technorati.com/tag/Technology/ </nowiki></pre>
as a rel-tag URL is treated as:
<pre><nowiki> http://technorati.com/tag/Technology </nowiki></pre>

== Encoding issues ==
Spaces can be encoded either as <code>+</code> or <code>%20</code>. Unicode characters are encoded as specified in [http://www.ietf.org/rfc/rfc3986.txt <nowiki>RFC 3986</nowiki>]. For example:

<pre><nowiki><a href="http://technorati.com/tag/Sant%C3%A9+et+bien-%C3%AAtre" rel="tag">Santé et bien-être</a> </nowiki></pre>

Note that if using Wikipedia as a tagspace, as discussed above, you should use <code>%20</code> as they remap '+' to <code>%2B</code>, causing a page with a plus sign in the title (which usually does not exist) to appear.

== Tags Are Visible Metadata ==
<code>rel="tag"</code> hyperlinks are intended to be visible links on pages and posts. This is in stark contrast to meta keywords (which were invisible and typically never revealed to readers), and thus is at least somewhat more resilient to the problems which plagued meta keywords.

Making tag hyperlinks visible has the additional benefit of making it more obvious to readers if a page is abusing tag links, and thus providing more peer pressure for better behavior. It also makes it more obvious to authors, who may not always be aware what invisible metadata is being generated on their behalf.

As a result the invisible tag link syntax variant: <code><link rel="tag" href="..." /></code> SHOULD NOT be supported by implementations.

==Examples in the Wild==
This section is '''informative'''.

The following sites have implemented rel-tag, and thus are a great place to start for anyone looking for examples "in the wild" to try parsing, indexing, organizing etc. If your site marked up with rel-tag, feel free to add it to the '''top''' of this list. Once the list grows too big, we'll make a separate wiki page.

* [http://www.idoneos.com Idoneos.com] uses rel-tag for conceptual links to its own tag space, a collection of 'concepts' (mostly spanish).
* [http://www.professionalontheweb.com Professional On The Web] uses rel-tag for user entered tags which categorize web professionals and freelancers.
* [https://www.coderesort.com/p/epicode/wiki/CloudCuckoo CloudCuckoo] (secure site but open to all) an [http://www.episerver.com EPiServer] module distributed free by [http://www.interakting.co.uk Interakting], generates tag clouds with rel-tag links.
* [http://www.lifetime.com Lifetime.com] uses rel- and rev-tags in all content pages.
* [http://www.my-warehouse.de the my-Warehouse shopsystem] implements rel-tags in box headings and categories links.
* Joseph Bergantine uses tags to categorize [http://bergantinedesign.us/wallpaper/ wallpapers] and [http://bergantinedesign.us/blog/my-name-is-rachel-corrie blog posts]
* [http://www.codesignville.com Codesignville] uses rel-tag to indicate content categories.
* [http://www.bossalive.com BossaLive] uses rel-tag for tagging music. Publishes rel-tags for album, artist and genre.
** Also uses [[hcard|hCard]] on user profile pages.
* [http://www.qmpeople.com/ qmpeople] Uses rel-tag for translated tags into english, french and italian to meet new friends in different countries.
* [http://www.keevu.com Keevu.com] uses rel-tag to indicate content categories on most pages, like [http://www.keevu.com/venues venues]
* [http://www.amazingincredible.com Amazing Incredible] uses rel-tag on content pages
* [http://www.auctionlink.com.au AuctionLink] uses rel-tag on [http://www.auctionlink.com.au/TagList/Auctioneers/ Auction Sales Listings] tags.
** Could also use [[hcard|hCard]], e.g. on [http://www.auctionlink.com.au/Auctioneers/Auctioneer/Bonhams_Goodman_1/] [[User:AndyMabbett|Andy Mabbett]]
* Christian Hess uses rel-tag on his [http://www.hess-cr.com homepage blog] and several other pages of his site.
* [http://spacedust.atspace.com/ Spacedust] uses rel-tag to mark up gallery pages.
* [http://my.opera.com/dstorey/blog/ My Opera] uses rel-tag for tags on all user's blog entries.
* [http://dev.opera.com/articles/view/making-wii-friendly-pages/ Dev Opera] uses rel-tag on all article tags.
* [http://www.international.unt.edu UNT International] uses rel-tag to indicate content categories on most pages
* [http://yedda.com Yedda] - Yedda publishes rel-tags for all of the tags the people entered on themselves as well as on all tags entered on questions asked on Yedda.
* [http://www.lingr.com Lingr] publishes rel-tags for all user entered tags.
* [http://odeo.com ODEO] [http://odeo.com/blog/2005/07/adding-microformats-to-odeo.html publishes] rel-tags for user entered tags.
* [http://eventful.com Eventful] publishes rel-tags for user entered tags.
* [http://spinn3r.com Spinn3r] implements rel-tag as well as RSS and Atom subject and categories.
* [http://www.weboffate.com Web of Fate] publishes rel-tags for future predictions.

== Implementations ==
This section is '''informative'''.

The following implementations have been developed which either generate or parse rel-tag links. If you have a rel-tag implementation, feel free to add it to the '''top''' of this list. Once the list grows too big, we'll make a separate wiki page.

* [http://www.textcube.org Textcube.org] makes a blogging tool, Textcube which generates rel-tag for tags on blog posts.
* [http://hashtags.org/ HashTags] tags Twitter posts, converting "#example" into a tag of "example"
* [http://ikiwiki.info ikiwiki] generates rel-tag for all tagged pages (as of version 2.6)
* [http://www.hubtag.com HubTag] helps users find a unique tag across the web for their event - eg. JohnAndBettysWeddingWimbledonMarch07
* [http://www.necctar.com Necctar] is a search engine exclusively based on tag microformat parsing and processing. Necctar uses tags entered by bloggers to index the world wide web
* Nutch has a [[rel-tag]] parser [http://www.mail-archive.com/nutch-commits@lucene.apache.org/msg01014.html committed to their svn repository].
* [http://www.webstandards.org/action/dwtf/microformats/ Dreamweaver Extension suite] from the [http://webstandards.org/ Web Standards Project] enables rel-tagging from within Dreamweaver 8.
* [http://scooch.gr0w.com/ Scooch] slide show creator allows authors to generate rel-tags and group slide shows by rel-tag via a list or cloud with tag usage count.
* The Freetag plugin for the [http://www.s9y.org Serendipity] blog software supports rel-tags on a per-entry basis, as well as inside of its tag clouds. (The Freetag plugin is available inside of SPARTACUS)
* [http://placenamehere.com/TXP/pnh_mf/ pnh_mf] is a plugin for [http://textpattern.com/ Textpattern] that supports embedding rel-tags and other microformats in templates and blog posts. Written by [http://placenamehere.com/ Chris Casciano].
* [http://www.truist.com/blog/493/trutags-a-tagging-plugin-for-textpattern tru_tags] is a plugin for [http://textpattern.com/ Textpattern] that supports rel-tagging blog posts via the Keywords field.
* [http://news.livejournal.com/86492.html?thread=24881884 LiveJournal] - see also [http://www.livejournal.com/support/faq.bml?cat=tags their FAQ regarding their tags support]
* [http://trac.labnotes.org/cgi-bin/trac.cgi/wiki/TagsLinks TagsLinks] Turn each tag into links that let you find related content on tagging services.
* [http://dev.wp-plugins.org/wiki/BunnysTechnoratiTags Tag plugin for WordPress]
** Note that some sites using WordPress (http://microformatique.com/ for instance) are getting incorrect tags. The tag is ?cat=12 instead of the actual tag value.
* [http://noone.org/blog/tags/Tagging Tag plugin for Blosxom]
* Technorati first implemented rel-tag in its [http://technorati.com/tag/ Technorati Tags] service. Technorati indexes rel-tag tags.
* [http://consumingexperience.blogspot.com/2005/12/updated-multiple-word-technorati-tag.html Greasemonkey script for Firefox that generates tags for Blogger]
* [http://tools.microformatic.com/help/xhtml/rel-lint/ rel-lint] is a validation tool by [[User:DrewMcLellan|Drew McLellan]] that will validate existence of rel-tag attributes.

== References ==
=== Normative References ===
* [http://www.w3.org/TR/REC-html40/ HTML 4]
* [http://www.w3.org/TR/xhtml1/ XHTML 1]
* [http://gmpg.org/xmdp/ XMDP]
* RFC 3986 specifies URL syntax. Section 3.3 specifies URL paths and path segments.

=== Informative References ===
* [[hreview|hReview]] uses rel-tag for tags and scalar tags
* [[xfolk|xFolk]] uses rel-tag to build a distributed remote resource tagging construct
* [http://developers.technorati.com/wiki/attentionxml Attention.XML] uses rel-tag for reader tagging of pages, posts, feeds
* [[hcard|hCard]] can use rel-tag for categories
* [[hcalendar|hCalendar]] can use rel-tag for categories
* [http://technorati.com/help/tags.html Using Technorati Tags]
* Contributed from http://developers.technorati.com/wiki/RelTag
* [http://microformatique.com/?p=61 Know your rel-tag] at microformatique.com

== Discussions ==
* Feedback is encouraged on the [[rel-tag-feedback]] page.
* See also [http://www.technorati.com/cosmos/referer.html blogs discussing this page].
* History: [http://www.powazek.com/2005/07/000532.html How Tags Happened at Technorati] by [http://www.powazek.com/ Derek Powazek]

=== Q&A ===
* If you have any questions about rel-tag, check the [[rel-faq|rel FAQ]] first for general rel attribute questions, then check the [[rel-tag-faq|rel-tag FAQ]], and then if you don't find answers, ask your question on the [http://microformats.org/discuss microformats-discuss] mailing list.

==Related pages==
{{rel-tag-related-pages}}

rel-tag

2008-07-12T15:27:06Z

WalterJJ: /* Implementations */

<h1> rel-tag </h1>

__TOC__

== Draft Specification 2005-01-10 ==
; Editors/Authors
:[http://tantek.com/ Tantek Çelik]
:[http://epeus.blogspot.com/ Kevin Marks]

;Concept
:[http://powazek.com/ Derek Powazek]

=== Copyright ===
{{MicroFormatCopyrightStatement2004}}
* [[User:Tantek|Tantek]]: I release all my contributions to this specification into the public domain and I encourage the other authors to do so as well.
** When all authors/editors have done so, we can remove the MicroFormatCopyrightStatement template reference and replace it with the MicroFormatPublicDomainContributionStatement.

=== Patents ===
{{MicroFormatPatentStatement}}

== Abstract ==
[[Rel-Tag]] is one of several [[MicroFormats]]. By adding <code>rel="tag"</code> to a hyperlink, a page indicates that the destination of that hyperlink is an author-designated "tag" (or keyword/subject) for the current page. Note that a tag may just refer to a major portion of the current page (i.e. a blog post). e.g. by placing this link on a page,

<pre><nowiki><a href="http://technorati.com/tag/tech" rel="tag">tech</a></nowiki></pre>

the author indicates that the page (or some portion of the page) has the tag "tech".

The linked page SHOULD exist, and it is the linked page, rather than the link text, that defines the tag. The last path component of the URL
is the text of the tag, so

<pre><nowiki><a href="http://technorati.com/tag/tech" rel="tag">fish</a></nowiki></pre>

would indicate the tag "tech" rather than "fish".

== Scope ==
rel="tag" is specifically designed for "tagging" content, typically web pages (or portions thereof, like blog posts).

rel="tag" is NOT designed for "tagging" arbitrary URLs or external content. There is demand for a general decentralized syntax for tagging URLs external to the current page, but this is not meant for that. See [[xfolk|xFolk]] and [[hreview|hReview]] for ways to tag arbitrary URLs.

If you need to define tags as part of a more specialized format, rel="tag" is the recommended way to do so, and [[xfolk|xFolk]], [[hreview|hReview]], [[hcard |hCard]] and [[hcalendar|hCalendar]] all do this.
== XMDP profile ==
<pre><nowiki>
<dl class="profile">
<dt id="rel">rel</dt>
<dd><p>
<a rel="help" href="http://www.w3.org/TR/html401/struct/links.html#adef-rel">
HTML4 definition of the 'rel' attribute.</a>
Here is an additional value.</p>
<dl>
<dt id="tag">tag</dt>
<dd>Indicates that the referred resource serves as a "tag",
or keyword/subject, for the referring page.</dd>
</dl>
</dd>
</dl>
</nowiki></pre>

== Tag Spaces ==

Tags are embedded in HTTP URIs in a well-defined manner so that the tag embedded in an HTTP URI can be mechanically extracted from that URI. Specifically, the last segment of the path portion of the URI (after the final "/" character) contains the tag value. For example, the URI <pre><nowiki>http://www.example.com/tags/foo</nowiki></pre> contains the tag "foo".

Thus, for the purposes of comparing two HTTP URIs as tags, the last segment of the path portion should be extracted and only that value (that value of the tag) should be compared.

''Need more formal language about comparison and extraction process.''

The destination of a rel="tag" hyperlink is required to be a tag space (a place that collates or defines tags), where the last segment of the path of the URL is the tag, e.g.

<pre><nowiki>http://technorati.com/tag/tech </nowiki></pre>

is a URL for the tag "tech".

Tags may only be placed in the URL path, and only in the last segment of the path. Tags may not be placed in query parameters or fragment identifiers. e.g.

<pre><nowiki>http://technorati.com/tag/tech?tag=fish#emu </nowiki></pre>

is still a URL for the tag "tech", not "fish" or "emu".

Since the only part of a tag space URL of which any structure is required is the last path segment, a tag space URL can be hosted at any domain. Authors may choose to link to a tag at a particular tag space in order to provide a specific meaning. E.g. a tag for technology could link to:

<pre><nowiki> http://en.wikipedia.org/wiki/Technology </nowiki></pre>

Trailing slashes in tag URLs are ignored, that is:

<pre><nowiki> http://technorati.com/tag/Technology/ </nowiki></pre>
as a rel-tag URL is treated as:
<pre><nowiki> http://technorati.com/tag/Technology </nowiki></pre>

== Encoding issues ==
Spaces can be encoded either as <code>+</code> or <code>%20</code>. Unicode characters are encoded as specified in [http://www.ietf.org/rfc/rfc3986.txt <nowiki>RFC 3986</nowiki>]. For example:

<pre><nowiki><a href="http://technorati.com/tag/Sant%C3%A9+et+bien-%C3%AAtre" rel="tag">Santé et bien-être</a> </nowiki></pre>

Note that if using Wikipedia as a tagspace, as discussed above, you should use <code>%20</code> as they remap '+' to <code>%2B</code>, causing a page with a plus sign in the title (which usually does not exist) to appear.

== Tags Are Visible Metadata ==
<code>rel="tag"</code> hyperlinks are intended to be visible links on pages and posts. This is in stark contrast to meta keywords (which were invisible and typically never revealed to readers), and thus is at least somewhat more resilient to the problems which plagued meta keywords.

Making tag hyperlinks visible has the additional benefit of making it more obvious to readers if a page is abusing tag links, and thus providing more peer pressure for better behavior. It also makes it more obvious to authors, who may not always be aware what invisible metadata is being generated on their behalf.

As a result the invisible tag link syntax variant: <code><link rel="tag" href="..." /></code> SHOULD NOT be supported by implementations.

==Examples in the Wild==
This section is '''informative'''.

The following sites have implemented rel-tag, and thus are a great place to start for anyone looking for examples "in the wild" to try parsing, indexing, organizing etc. If your site marked up with rel-tag, feel free to add it to the '''top''' of this list. Once the list grows too big, we'll make a separate wiki page.

* [http://www.professionalontheweb.com Professional On The Web] uses rel-tag for user entered tags which categorize web professionals and freelancers.
* [https://www.coderesort.com/p/epicode/wiki/CloudCuckoo CloudCuckoo] (secure site but open to all) an [http://www.episerver.com EPiServer] module distributed free by [http://www.interakting.co.uk Interakting], generates tag clouds with rel-tag links.
* [http://www.lifetime.com Lifetime.com] uses rel- and rev-tags in all content pages.
* [http://www.my-warehouse.de the my-Warehouse shopsystem] implements rel-tags in box headings and categories links.
* Joseph Bergantine uses tags to categorize [http://bergantinedesign.us/wallpaper/ wallpapers] and [http://bergantinedesign.us/blog/my-name-is-rachel-corrie blog posts]
* [http://www.codesignville.com Codesignville] uses rel-tag to indicate content categories.
* [http://www.bossalive.com BossaLive] uses rel-tag for tagging music. Publishes rel-tags for album, artist and genre.
** Also uses [[hcard|hCard]] on user profile pages.
* [http://www.qmpeople.com/ qmpeople] Uses rel-tag for translated tags into english, french and italian to meet new friends in different countries.
* [http://www.keevu.com Keevu.com] uses rel-tag to indicate content categories on most pages, like [http://www.keevu.com/venues venues]
* [http://www.amazingincredible.com Amazing Incredible] uses rel-tag on content pages
* [http://www.auctionlink.com.au AuctionLink] uses rel-tag on [http://www.auctionlink.com.au/TagList/Auctioneers/ Auction Sales Listings] tags.
** Could also use [[hcard|hCard]], e.g. on [http://www.auctionlink.com.au/Auctioneers/Auctioneer/Bonhams_Goodman_1/] [[User:AndyMabbett|Andy Mabbett]]
* Christian Hess uses rel-tag on his [http://www.hess-cr.com homepage blog] and several other pages of his site.
* [http://spacedust.atspace.com/ Spacedust] uses rel-tag to mark up gallery pages.
* [http://my.opera.com/dstorey/blog/ My Opera] uses rel-tag for tags on all user's blog entries.
* [http://dev.opera.com/articles/view/making-wii-friendly-pages/ Dev Opera] uses rel-tag on all article tags.
* [http://www.international.unt.edu UNT International] uses rel-tag to indicate content categories on most pages
* [http://yedda.com Yedda] - Yedda publishes rel-tags for all of the tags the people entered on themselves as well as on all tags entered on questions asked on Yedda.
* [http://www.lingr.com Lingr] publishes rel-tags for all user entered tags.
* [http://odeo.com ODEO] [http://odeo.com/blog/2005/07/adding-microformats-to-odeo.html publishes] rel-tags for user entered tags.
* [http://eventful.com Eventful] publishes rel-tags for user entered tags.
* [http://spinn3r.com Spinn3r] implements rel-tag as well as RSS and Atom subject and categories.
* [http://www.weboffate.com Web of Fate] publishes rel-tags for future predictions.

== Implementations ==
This section is '''informative'''.

The following implementations have been developed which either generate or parse rel-tag links. If you have a rel-tag implementation, feel free to add it to the '''top''' of this list. Once the list grows too big, we'll make a separate wiki page.

* [http://www.textcube.org Textcube.org] makes a blogging tool, Textcube which generates rel-tag for tags on blog posts.
* [http://hashtags.org/ HashTags] tags Twitter posts, converting "#example" into a tag of "example"
* [http://ikiwiki.info ikiwiki] generates rel-tag for all tagged pages (as of version 2.6)
* [http://www.hubtag.com HubTag] helps users find a unique tag across the web for their event - eg. JohnAndBettysWeddingWimbledonMarch07
* [http://www.necctar.com Necctar] is a search engine exclusively based on tag microformat parsing and processing. Necctar uses tags entered by bloggers to index the world wide web
* Nutch has a [[rel-tag]] parser [http://www.mail-archive.com/nutch-commits@lucene.apache.org/msg01014.html committed to their svn repository].
* [http://www.webstandards.org/action/dwtf/microformats/ Dreamweaver Extension suite] from the [http://webstandards.org/ Web Standards Project] enables rel-tagging from within Dreamweaver 8.
* [http://scooch.gr0w.com/ Scooch] slide show creator allows authors to generate rel-tags and group slide shows by rel-tag via a list or cloud with tag usage count.
* The Freetag plugin for the [http://www.s9y.org Serendipity] blog software supports rel-tags on a per-entry basis, as well as inside of its tag clouds. (The Freetag plugin is available inside of SPARTACUS)
* [http://placenamehere.com/TXP/pnh_mf/ pnh_mf] is a plugin for [http://textpattern.com/ Textpattern] that supports embedding rel-tags and other microformats in templates and blog posts. Written by [http://placenamehere.com/ Chris Casciano].
* [http://www.truist.com/blog/493/trutags-a-tagging-plugin-for-textpattern tru_tags] is a plugin for [http://textpattern.com/ Textpattern] that supports rel-tagging blog posts via the Keywords field.
* [http://news.livejournal.com/86492.html?thread=24881884 LiveJournal] - see also [http://www.livejournal.com/support/faq.bml?cat=tags their FAQ regarding their tags support]
* [http://trac.labnotes.org/cgi-bin/trac.cgi/wiki/TagsLinks TagsLinks] Turn each tag into links that let you find related content on tagging services.
* [http://dev.wp-plugins.org/wiki/BunnysTechnoratiTags Tag plugin for WordPress]
** Note that some sites using WordPress (http://microformatique.com/ for instance) are getting incorrect tags. The tag is ?cat=12 instead of the actual tag value.
* [http://noone.org/blog/tags/Tagging Tag plugin for Blosxom]
* Technorati first implemented rel-tag in its [http://technorati.com/tag/ Technorati Tags] service. Technorati indexes rel-tag tags.
* [http://consumingexperience.blogspot.com/2005/12/updated-multiple-word-technorati-tag.html Greasemonkey script for Firefox that generates tags for Blogger]
* [http://tools.microformatic.com/help/xhtml/rel-lint/ rel-lint] is a validation tool by [[User:DrewMcLellan|Drew McLellan]] that will validate existence of rel-tag attributes.

== References ==
=== Normative References ===
* [http://www.w3.org/TR/REC-html40/ HTML 4]
* [http://www.w3.org/TR/xhtml1/ XHTML 1]
* [http://gmpg.org/xmdp/ XMDP]
* RFC 3986 specifies URL syntax. Section 3.3 specifies URL paths and path segments.

=== Informative References ===
* [[hreview|hReview]] uses rel-tag for tags and scalar tags
* [[xfolk|xFolk]] uses rel-tag to build a distributed remote resource tagging construct
* [http://developers.technorati.com/wiki/attentionxml Attention.XML] uses rel-tag for reader tagging of pages, posts, feeds
* [[hcard|hCard]] can use rel-tag for categories
* [[hcalendar|hCalendar]] can use rel-tag for categories
* [http://technorati.com/help/tags.html Using Technorati Tags]
* Contributed from http://developers.technorati.com/wiki/RelTag
* [http://microformatique.com/?p=61 Know your rel-tag] at microformatique.com

== Discussions ==
* Feedback is encouraged on the [[rel-tag-feedback]] page.
* See also [http://www.technorati.com/cosmos/referer.html blogs discussing this page].
* History: [http://www.powazek.com/2005/07/000532.html How Tags Happened at Technorati] by [http://www.powazek.com/ Derek Powazek]

=== Q&A ===
* If you have any questions about rel-tag, check the [[rel-faq|rel FAQ]] first for general rel attribute questions, then check the [[rel-tag-faq|rel-tag FAQ]], and then if you don't find answers, ask your question on the [http://microformats.org/discuss microformats-discuss] mailing list.

==Related pages==
{{rel-tag-related-pages}}

rel-tag

2008-07-12T15:25:36Z

WalterJJ: /* Implementations */

<h1> rel-tag </h1>

__TOC__

== Draft Specification 2005-01-10 ==
; Editors/Authors
:[http://tantek.com/ Tantek Çelik]
:[http://epeus.blogspot.com/ Kevin Marks]

;Concept
:[http://powazek.com/ Derek Powazek]

=== Copyright ===
{{MicroFormatCopyrightStatement2004}}
* [[User:Tantek|Tantek]]: I release all my contributions to this specification into the public domain and I encourage the other authors to do so as well.
** When all authors/editors have done so, we can remove the MicroFormatCopyrightStatement template reference and replace it with the MicroFormatPublicDomainContributionStatement.

=== Patents ===
{{MicroFormatPatentStatement}}

== Abstract ==
[[Rel-Tag]] is one of several [[MicroFormats]]. By adding <code>rel="tag"</code> to a hyperlink, a page indicates that the destination of that hyperlink is an author-designated "tag" (or keyword/subject) for the current page. Note that a tag may just refer to a major portion of the current page (i.e. a blog post). e.g. by placing this link on a page,

<pre><nowiki><a href="http://technorati.com/tag/tech" rel="tag">tech</a></nowiki></pre>

the author indicates that the page (or some portion of the page) has the tag "tech".

The linked page SHOULD exist, and it is the linked page, rather than the link text, that defines the tag. The last path component of the URL
is the text of the tag, so

<pre><nowiki><a href="http://technorati.com/tag/tech" rel="tag">fish</a></nowiki></pre>

would indicate the tag "tech" rather than "fish".

== Scope ==
rel="tag" is specifically designed for "tagging" content, typically web pages (or portions thereof, like blog posts).

rel="tag" is NOT designed for "tagging" arbitrary URLs or external content. There is demand for a general decentralized syntax for tagging URLs external to the current page, but this is not meant for that. See [[xfolk|xFolk]] and [[hreview|hReview]] for ways to tag arbitrary URLs.

If you need to define tags as part of a more specialized format, rel="tag" is the recommended way to do so, and [[xfolk|xFolk]], [[hreview|hReview]], [[hcard |hCard]] and [[hcalendar|hCalendar]] all do this.
== XMDP profile ==
<pre><nowiki>
<dl class="profile">
<dt id="rel">rel</dt>
<dd><p>
<a rel="help" href="http://www.w3.org/TR/html401/struct/links.html#adef-rel">
HTML4 definition of the 'rel' attribute.</a>
Here is an additional value.</p>
<dl>
<dt id="tag">tag</dt>
<dd>Indicates that the referred resource serves as a "tag",
or keyword/subject, for the referring page.</dd>
</dl>
</dd>
</dl>
</nowiki></pre>

== Tag Spaces ==

Tags are embedded in HTTP URIs in a well-defined manner so that the tag embedded in an HTTP URI can be mechanically extracted from that URI. Specifically, the last segment of the path portion of the URI (after the final "/" character) contains the tag value. For example, the URI <pre><nowiki>http://www.example.com/tags/foo</nowiki></pre> contains the tag "foo".

Thus, for the purposes of comparing two HTTP URIs as tags, the last segment of the path portion should be extracted and only that value (that value of the tag) should be compared.

''Need more formal language about comparison and extraction process.''

The destination of a rel="tag" hyperlink is required to be a tag space (a place that collates or defines tags), where the last segment of the path of the URL is the tag, e.g.

<pre><nowiki>http://technorati.com/tag/tech </nowiki></pre>

is a URL for the tag "tech".

Tags may only be placed in the URL path, and only in the last segment of the path. Tags may not be placed in query parameters or fragment identifiers. e.g.

<pre><nowiki>http://technorati.com/tag/tech?tag=fish#emu </nowiki></pre>

is still a URL for the tag "tech", not "fish" or "emu".

Since the only part of a tag space URL of which any structure is required is the last path segment, a tag space URL can be hosted at any domain. Authors may choose to link to a tag at a particular tag space in order to provide a specific meaning. E.g. a tag for technology could link to:

<pre><nowiki> http://en.wikipedia.org/wiki/Technology </nowiki></pre>

Trailing slashes in tag URLs are ignored, that is:

<pre><nowiki> http://technorati.com/tag/Technology/ </nowiki></pre>
as a rel-tag URL is treated as:
<pre><nowiki> http://technorati.com/tag/Technology </nowiki></pre>

== Encoding issues ==
Spaces can be encoded either as <code>+</code> or <code>%20</code>. Unicode characters are encoded as specified in [http://www.ietf.org/rfc/rfc3986.txt <nowiki>RFC 3986</nowiki>]. For example:

<pre><nowiki><a href="http://technorati.com/tag/Sant%C3%A9+et+bien-%C3%AAtre" rel="tag">Santé et bien-être</a> </nowiki></pre>

Note that if using Wikipedia as a tagspace, as discussed above, you should use <code>%20</code> as they remap '+' to <code>%2B</code>, causing a page with a plus sign in the title (which usually does not exist) to appear.

== Tags Are Visible Metadata ==
<code>rel="tag"</code> hyperlinks are intended to be visible links on pages and posts. This is in stark contrast to meta keywords (which were invisible and typically never revealed to readers), and thus is at least somewhat more resilient to the problems which plagued meta keywords.

Making tag hyperlinks visible has the additional benefit of making it more obvious to readers if a page is abusing tag links, and thus providing more peer pressure for better behavior. It also makes it more obvious to authors, who may not always be aware what invisible metadata is being generated on their behalf.

As a result the invisible tag link syntax variant: <code><link rel="tag" href="..." /></code> SHOULD NOT be supported by implementations.

==Examples in the Wild==
This section is '''informative'''.

The following sites have implemented rel-tag, and thus are a great place to start for anyone looking for examples "in the wild" to try parsing, indexing, organizing etc. If your site marked up with rel-tag, feel free to add it to the '''top''' of this list. Once the list grows too big, we'll make a separate wiki page.

* [http://www.professionalontheweb.com Professional On The Web] uses rel-tag for user entered tags which categorize web professionals and freelancers.
* [https://www.coderesort.com/p/epicode/wiki/CloudCuckoo CloudCuckoo] (secure site but open to all) an [http://www.episerver.com EPiServer] module distributed free by [http://www.interakting.co.uk Interakting], generates tag clouds with rel-tag links.
* [http://www.lifetime.com Lifetime.com] uses rel- and rev-tags in all content pages.
* [http://www.my-warehouse.de the my-Warehouse shopsystem] implements rel-tags in box headings and categories links.
* Joseph Bergantine uses tags to categorize [http://bergantinedesign.us/wallpaper/ wallpapers] and [http://bergantinedesign.us/blog/my-name-is-rachel-corrie blog posts]
* [http://www.codesignville.com Codesignville] uses rel-tag to indicate content categories.
* [http://www.bossalive.com BossaLive] uses rel-tag for tagging music. Publishes rel-tags for album, artist and genre.
** Also uses [[hcard|hCard]] on user profile pages.
* [http://www.qmpeople.com/ qmpeople] Uses rel-tag for translated tags into english, french and italian to meet new friends in different countries.
* [http://www.keevu.com Keevu.com] uses rel-tag to indicate content categories on most pages, like [http://www.keevu.com/venues venues]
* [http://www.amazingincredible.com Amazing Incredible] uses rel-tag on content pages
* [http://www.auctionlink.com.au AuctionLink] uses rel-tag on [http://www.auctionlink.com.au/TagList/Auctioneers/ Auction Sales Listings] tags.
** Could also use [[hcard|hCard]], e.g. on [http://www.auctionlink.com.au/Auctioneers/Auctioneer/Bonhams_Goodman_1/] [[User:AndyMabbett|Andy Mabbett]]
* Christian Hess uses rel-tag on his [http://www.hess-cr.com homepage blog] and several other pages of his site.
* [http://spacedust.atspace.com/ Spacedust] uses rel-tag to mark up gallery pages.
* [http://my.opera.com/dstorey/blog/ My Opera] uses rel-tag for tags on all user's blog entries.
* [http://dev.opera.com/articles/view/making-wii-friendly-pages/ Dev Opera] uses rel-tag on all article tags.
* [http://www.international.unt.edu UNT International] uses rel-tag to indicate content categories on most pages
* [http://yedda.com Yedda] - Yedda publishes rel-tags for all of the tags the people entered on themselves as well as on all tags entered on questions asked on Yedda.
* [http://www.lingr.com Lingr] publishes rel-tags for all user entered tags.
* [http://odeo.com ODEO] [http://odeo.com/blog/2005/07/adding-microformats-to-odeo.html publishes] rel-tags for user entered tags.
* [http://eventful.com Eventful] publishes rel-tags for user entered tags.
* [http://spinn3r.com Spinn3r] implements rel-tag as well as RSS and Atom subject and categories.
* [http://www.weboffate.com Web of Fate] publishes rel-tags for future predictions.

== Implementations ==
This section is '''informative'''.

The following implementations have been developed which either generate or parse rel-tag links. If you have a rel-tag implementation, feel free to add it to the '''top''' of this list. Once the list grows too big, we'll make a separate wiki page.

* [http://www.idoneos.com Idoneos.com] uses rel-tag for conceptual links to its own tag space, a collection of 'concepts' (mostly spanish).
* [http://www.textcube.org Textcube.org] makes a blogging tool, Textcube which generates rel-tag for tags on blog posts.
* [http://hashtags.org/ HashTags] tags Twitter posts, converting "#example" into a tag of "example"
* [http://ikiwiki.info ikiwiki] generates rel-tag for all tagged pages (as of version 2.6)
* [http://www.hubtag.com HubTag] helps users find a unique tag across the web for their event - eg. JohnAndBettysWeddingWimbledonMarch07
* [http://www.necctar.com Necctar] is a search engine exclusively based on tag microformat parsing and processing. Necctar uses tags entered by bloggers to index the world wide web
* Nutch has a [[rel-tag]] parser [http://www.mail-archive.com/nutch-commits@lucene.apache.org/msg01014.html committed to their svn repository].
* [http://www.webstandards.org/action/dwtf/microformats/ Dreamweaver Extension suite] from the [http://webstandards.org/ Web Standards Project] enables rel-tagging from within Dreamweaver 8.
* [http://scooch.gr0w.com/ Scooch] slide show creator allows authors to generate rel-tags and group slide shows by rel-tag via a list or cloud with tag usage count.
* The Freetag plugin for the [http://www.s9y.org Serendipity] blog software supports rel-tags on a per-entry basis, as well as inside of its tag clouds. (The Freetag plugin is available inside of SPARTACUS)
* [http://placenamehere.com/TXP/pnh_mf/ pnh_mf] is a plugin for [http://textpattern.com/ Textpattern] that supports embedding rel-tags and other microformats in templates and blog posts. Written by [http://placenamehere.com/ Chris Casciano].
* [http://www.truist.com/blog/493/trutags-a-tagging-plugin-for-textpattern tru_tags] is a plugin for [http://textpattern.com/ Textpattern] that supports rel-tagging blog posts via the Keywords field.
* [http://news.livejournal.com/86492.html?thread=24881884 LiveJournal] - see also [http://www.livejournal.com/support/faq.bml?cat=tags their FAQ regarding their tags support]
* [http://trac.labnotes.org/cgi-bin/trac.cgi/wiki/TagsLinks TagsLinks] Turn each tag into links that let you find related content on tagging services.
* [http://dev.wp-plugins.org/wiki/BunnysTechnoratiTags Tag plugin for WordPress]
** Note that some sites using WordPress (http://microformatique.com/ for instance) are getting incorrect tags. The tag is ?cat=12 instead of the actual tag value.
* [http://noone.org/blog/tags/Tagging Tag plugin for Blosxom]
* Technorati first implemented rel-tag in its [http://technorati.com/tag/ Technorati Tags] service. Technorati indexes rel-tag tags.
* [http://consumingexperience.blogspot.com/2005/12/updated-multiple-word-technorati-tag.html Greasemonkey script for Firefox that generates tags for Blogger]
* [http://tools.microformatic.com/help/xhtml/rel-lint/ rel-lint] is a validation tool by [[User:DrewMcLellan|Drew McLellan]] that will validate existence of rel-tag attributes.

== References ==
=== Normative References ===
* [http://www.w3.org/TR/REC-html40/ HTML 4]
* [http://www.w3.org/TR/xhtml1/ XHTML 1]
* [http://gmpg.org/xmdp/ XMDP]
* RFC 3986 specifies URL syntax. Section 3.3 specifies URL paths and path segments.

=== Informative References ===
* [[hreview|hReview]] uses rel-tag for tags and scalar tags
* [[xfolk|xFolk]] uses rel-tag to build a distributed remote resource tagging construct
* [http://developers.technorati.com/wiki/attentionxml Attention.XML] uses rel-tag for reader tagging of pages, posts, feeds
* [[hcard|hCard]] can use rel-tag for categories
* [[hcalendar|hCalendar]] can use rel-tag for categories
* [http://technorati.com/help/tags.html Using Technorati Tags]
* Contributed from http://developers.technorati.com/wiki/RelTag
* [http://microformatique.com/?p=61 Know your rel-tag] at microformatique.com

== Discussions ==
* Feedback is encouraged on the [[rel-tag-feedback]] page.
* See also [http://www.technorati.com/cosmos/referer.html blogs discussing this page].
* History: [http://www.powazek.com/2005/07/000532.html How Tags Happened at Technorati] by [http://www.powazek.com/ Derek Powazek]

=== Q&A ===
* If you have any questions about rel-tag, check the [[rel-faq|rel FAQ]] first for general rel attribute questions, then check the [[rel-tag-faq|rel-tag FAQ]], and then if you don't find answers, ask your question on the [http://microformats.org/discuss microformats-discuss] mailing list.

==Related pages==
{{rel-tag-related-pages}}