hCard is a simple, open, distributed contact information format for people, companies, and organizations, which is suitable for embedding in (X)HTML, Atom, RSS, and arbitrary XML. hCard is a 1:1 representation of the vCard standard (RFC2426) in XHTML, one of several open microformat standards.
- 1 hCard
- 1.1 Draft Specification
- 1.2 Introduction
- 1.3 Semantic XHTML Design Principles
- 1.4 Format
- 1.4.1 In General
- 1.4.2 More Semantic Equivalents
- 1.4.3 Singular vs. Multivalued Properties
- 1.4.4 Human vs. Machine readable
- 1.4.5 Value excerpting
- 1.4.6 Property Exceptions
- 1.4.7 Organization Contact Info
- 1.4.8 Implied "n" Optimization
- 1.4.9 Implied "nickname" Optimization
- 1.4.10 Implied "organization-name" Optimization
- 1.4.11 Root Class Name
- 1.4.12 Property List
- 1.4.13 XMDP Profile
- 1.4.14 Parsing Details
- 1.5 Examples
- 1.6 Examples in the wild
- 1.7 Implementations
- 1.8 Additional Applications
- 1.9 References
- 1.10 Related Pages
- 1.11 Further Reading
This specification is (C) 2004-2021 by the authors. However, the authors intend to submit (or already have submitted, see details in the spec) this specification to a standards body with a liberal copyright/licensing policy such as the GMPG, IETF, and/or W3C. Anyone wishing to contribute should read their copyright principles, policies and licenses (e.g. the GMPG Principles) and agree to them, including licensing of all contributions under all required licenses (e.g. CC-by 1.0 and later), before contributing.
Inspiration and Acknowledgments
Thanks to: my good friend Vadim who introduced me to vCard many years ago, and if I'd only paid more attention then, perhaps I could have helped a lot of people avoid wasting a lot of time reinventing various standards wheels.
The vCard standard (RFC2426), has been broadly interoperably implemented (e.g. Apple's "Address Book" application built into MacOSX).
In addition, many bloggers identify themselves by name and discuss their friends and family. With just a tad bit of structure, bloggers can discuss people in their blog(s) in such a way that spiders and other aggregators can retrieve this information, automatically convert them to vCards, and use them in any vCard application or service.
This specification introduces the hCard format, which is a 1:1 representation of the aforementioned vCard standard, in semantic XHTML. Bloggers can both embed vCards directly in their web pages, and style them with CSS to make them appear as desired. In addition, hCard enables applications to retrieve information about such vCards directly from web pages without having to reference a separate file.
Use the hCard creator, copy the HTML code it generates to your blog or website to publish your contact info.
Semantic XHTML Design Principles
Note: the Semantic XHTML Design Principles were written primarily within the context of developing hCard and hCalendar, thus it may be easier to understand these principles in the context of the hCard design methodology (i.e. read that first). Tantek
XHTML is built on XML, and thus XHTML based formats can be used not only for convenient display presentation, but also for general purpose data exchange. In many ways, XHTML based formats exemplify the best of both HTML and XML worlds. However, when building XHTML based formats, it helps to have a guiding set of principles.
- Reuse the schema (names, objects, properties, values, types, hierarchies, constraints) as much as possible from pre-existing, established, well-supported standards by reference. Avoid restating constraints expressed in the source standard. Informative mentions are ok.
- For types with multiple components, use nested elements with class names equivalent to the names of the components.
- Plural components are made singular, and thus multiple nested elements are used to represent multiple text values that are comma-delimited.
- Use the most accurately precise semantic XHTML building block for each object etc.
- Otherwise use a generic structural element (e.g.
<div>), or the appropriate contextual element (e.g. an
- Use class names based on names from the original schema, unless the semantic XHTML building block precisely represents that part of the original schema. If names in the source schema are case-insensitive, then use an all lowercase equivalent. Components names implicit in prose (rather than explicit in the defined schema) should also use lowercase equivalents for ease of use. Spaces in component names become dash '-' characters.
- Finally, if the format of the data according to the original schema is too long and/or not human-friendly, use
<abbr>instead of a generic structural element, and place the literal data into the 'title' attribute (where abbr expansions go), and the more brief and human readable equivalent into the element itself. Further informative explanation of this use of
<abbr>: Human vs. ISO8601 dates problem solved
The vCard standard (RFC2426) forms the basis of hCard.
The basic format of hCard is to use vCard object/property names in lower-case for class names, and to map the nesting of vCard objects directly into nested XHTML elements.
More Semantic Equivalents
However, for some properties there is a more semantic equivalent, and therefore they get special treatment, e.g.:
URLin vCard becomes
<a class="url" href="...">...</a>inside the element with
<a class="email" href="mailto:...">...</a>
PHOTOin vCard becomes
<img class="photo" src="..." alt="Photo of ..." />
Singular vs. Multivalued Properties
For properties which are singular (e.g. "N" and "FN"), the first descendant element with that class should take effect, any others being ignored.
For properties which can be plural (e.g. "TEL"), each class instance should create a instance of that property.
Plural Properties Singularized
Since plural property names become their singular equivalents, even if the original plural property permitted only a single value with multiple components, those multiple components are represented each with their own singularly named property and the the property is effectively multivalued and subject to the above treatment of multivalued properties.
Human vs. Machine readable
<abbr> element is used for a property, then the '
title' attribute of the
<abbr> element is the value of the property, instead of the contents of the element, which instead provide a human presentable version of the value.
Similarly, if an
<img> element is used for one or more properties, it must be treated as follows:
- For the "PHOTO" property and any other property that takes a URL as its value, the
src="..."attribute provides the property value.
- For other properties, the
alt' attribute is the value of the property.
Sometimes only part of an element which is the equivalent for a property should be used for the value of the property. This typically occurs when a property has a subtype, like TEL. For this purpose, the special class name "
value" is introduced to excerpt out the subset of the element that is the value of the property. E.g. here is an hCard fragment for marking up a home phone number:
<span class="tel"> <span class="type">home</span>: <span class="value">+1.415.555.1212</span> </span>
This hCard fragment could be displayed as:
vCard has several properties which either do not make sense on, or are already implied within the context of a web page. This section explains what to (not) do with them.
- NAME, PROFILE, SOURCE, PRODID, VERSION properties as defined in Sections 2.1.2, 2.1.3, 2.1.4, 3.6.3, 3.6.9 of RFC 2426. Content publishers MUST NOT use these properties in their hCards, and as such, hCard consumers/parsers MUST IGNORE these properties if they are found within an hCard. Instead. hCard to vCard converters SHOULD use the title of the page where the hCard is found (e.g. the
<title>element in (X)HTML documents) to construct the NAME property, MAY output a PROFILE value of "
VCARD" per RFC 2426, SHOULD use the URL of the page where the hCard is found to construct the SOURCE property (e.g. perhaps as a parameter to a URL/service that converts hCards to vCards), for an output vCard stream (e.g. a .vcf file). Only services/applications that output actual vCards should write the PRODID property, with the product identifier for said service/application. Similarly only such services/applications should write the VERSION property, with the value "3.0" (without quotes) per RFC2426 Section 3.6.9.
Organization Contact Info
If the "FN" and "ORG" properties have the exact same value (typically because they are set on the same element, e.g. class="fn org"), then the hCard represents contact information for a company or organization and should be treated as such. In this case the author MUST also NOT set the "N" property, or set it (and any sub-properties) explicitly to the empty string "". Thus parsers should handle the missing "N" property in this case by implying empty values for all the "N" sub-properties.
Implied "n" Optimization
Although vCard requires that the "N" property be present, the authors of the vCard specification (RFC 2426) themselves do not include "N" properties in their vCards near the end of the spec (p.38). This apparent contradiction can be resolved by simply allowing the "FN" property to imply "N" property values in typical cases provided in the spec. We do so explicitly in hCard.
If "FN" and "ORG" are not the same (see previous section), and the value of the "FN" property is exactly two words (separated by whitespace), and there is no explicit "N" property, then the "N" property is inferred from the "FN" property. For "FN"s with either one word see below, and for three or more, the author MUST explicitly markup the "N", except for the organization contact info case, see above for that.
- The content of "FN" is broken into two "words" separated by whitespace.
- The first word of the "FN" is interpreted as the "given-name" for the "N" property.
- The second/last word of the "FN" is interpreted as the "family-name" for the "N" property.
- Exception: If the first word ends in a "," comma OR if the second word is a single character (optionally followed by a period "."), then the first word (minus the comma at the end if any) is interpreted as the "family-name" and the second word is interpreted as the "given-name".
This allows simplification in the typical case of people stating:
- given-name (space) family-name
- family-name (comma) given-name
- family-name (comma) given-name-first-initial
- family-name (space) given-name-first-initial (optional period)
Implied "nickname" Optimization
Due to the prevalence of the use of nicknames/handles/usernames on the Web in actual content published on the Web (e.g. authors of reviews), hCard also has an implied "nickname" optimization to handle this.
Similar to the implied "n" optimization, if "FN" and "ORG" are not the same, and the value of the "FN" property is exactly one word, and there is no explicit "N" property, then:
- The content of the "FN" is treated as a "nickname" property value.
- Parsers should handle the missing "N" property by implying empty values for all the "N" sub-properties.
Note: the hCard may have additional explicit "nickname" property values in addition to the implied nickname.
Implied "organization-name" Optimization
The "ORG" property has two subproperties, organization-name and organization-unit. Very often authors only publish the organization-name. Thus if an "ORG" property has no "organization-name" inside it, then its entire contents MUST be treated as the "organization-name".
Root Class Name
The root class name for an hCard is "vcard".
This is the list of properties (and subproperties, in parantheses, like this) in hCard, taken from vCard:
- fn, n (family-name, given-name, additional-name, honorific-prefix, honorific-suffix), nickname, sort-string
- url, email (type, value), tel (type, value)
- adr (post-office-box, extended-address, street-address, locality, region, postal-code, country-name, type, value), label
- geo (latitude, longitude), tz
- photo, logo, sound, bday
- title, role, org (organization-name, organization-unit)
- category, note
- class, key, mailer, uid, rev
type subproperty values
The 'type' subproperty in particular takes different values depending on which property it is a subproperty of. These 'type' subproperty values are case-INSENSITIVE, meaning "Home" is the same as "home", as well as multivalued, e.g. a tel can be home and preferred:
<span class="tel"><span class="type">Home</span> (<span class="type">pref</span>erred): <span class="value">+1.415.555.1212</span> </span>
The following lists are informative. See RFC2426 sections 3.2.1 ADR, 3.3.1 TEL, and 3.3.2 EMAIL respectively for normative type values. They are repeated here for convenience. Default type subproperty value(s) is(are) first in each list and indicated in ALL CAPS. types may be multivalued.
- adr type: INTL, POSTAL, PARCEL, WORK, dom, home, pref
- tel type: VOICE, home, msg, work, pref, fax, cell, video, pager, bbs, modem, car, isdn, pcs
- email type: INTERNET, x400, pref, "other IANA registered address types"
See hCard parsing.
This section is informative.
Here is a sample vCard:
BEGIN:VCARD VERSION:3.0 N:Çelik;Tantek FN:Tantek Çelik URL:http://tantek.com ORG:Technorati END:VCARD
and an equivalent in hCard with various elements optimized appropriately. See hCard Example 1 for the derivation.
<div class="vcard"> <a class="url fn" href="http://tantek.com/">Tantek Çelik</a> <div class="org">Technorati</div> </div>
This hCard might be displayed as:
Note: The version information is unnecessary in hCard markup directly since the version will be defined by the profile of hCard that is used/referred to in the 'profile' attribute of the <head> element.
See hCard examples for more examples, including all examples from vCard RFC 2426 converted into hCard.
Examples in the wild
This section is informative.
The following sites have published hCards, and thus are a great place to start for anyone looking for examples "in the wild" to try parsing, indexing, organizing etc. If you have an hCard on your own page, feel free to add it to the top of this list. Once the list grows too big, we'll make a separate wiki page.
Please add new examples to this section.
- Ning's cloneable Group app uses fuzzy matching to map custom fields to hCard markup on its profile pages.
- Chris Messina' ClaimID hCard
- Chris Messina' hCard
- Flock About
- Agenda: W3C Technical Plenary Day, March 1 2006 has hCard and hCalendar markup. (original here).
- GrowSearch Launched (Press Release) uses an hCard to provide Press Contact Point.
- The National Arbor Day Foundation has started using hCards for their upcoming conferences.
- The Multipack has numerous hCards, especially on the members page, as well as the next meeting information.
- Justin McDowell used an hCard when referring to a person in his blog post
- Dave Cardwell has included his hCard in his Curriculum Vitae.
- Shaun Shull has written a great post on How Microformats Affect SEO, and has included his hCard as one of the examples.
- Jesse Skinner has written a simple tutorial with examples
- 2006 W3C Technical Plenary Week has marked up the venue, contacts, and program committee members all with hCard.
- AVF-Nexus have a hCard on their contact page - (by Creation")
- Andrew White posted his hCard and blogged about it.
- Oleg "2sheds" Kourapov in his blog (X2V) has turned personal profile into hCard (X2V) and his blogroll - into combination XFN/hCards (X2V)
- Approved Design Consultancy have a hCard on their contact page as well as on their people section - (by Creation")
- Ben Buchanan and Colin Morris have implemented hCards and vCards for the Griffith University online phone book. Eg. Ben's vCard and Colin's vCard
- WWF-Australia contact details page
- Pete Prodoehl used the hCard format on his Contact page
- amette uses the hCard format in a module of his TikiWiki powered blog
- Oren Sreebny has an hcard on his blog main index template
- Aiden Kenny hasn't published his hCard yet, but he has published his hCard icon:
- Andy Hume uses the hcard format to mark-up the names and URLs of commentors on his blog.
- BidClix's Contact BidClix page has it's contact info marked up with an hCard.
- Brian Suda has managed to embed a photo in his hCard through the data uri scheme by converting the image to BASE64 code. View the Source to see how this is accomplished. The X2V link will extract the image and encode it for a vCard which will be displayed in some address book applications.
- Cinema Treasures uses hCard to markup venue information for 10,000+ movie theaters.
- Dan Connolly's index of events and talks has hCards for many of the people he has met at those events. In Mar 2006, he moved a bunch of hotel contact info from his PDA to this page; it's now up to 32 hCards.
- Don Crowley has published his hCard as well as a nifty hCard button:
- Douglas W. Clifton added all types of contact information
- EVDB, the Events and Venues Database, publishes all venue detail pages with embedded hCards.
- Iowa Military Veterans Band Contacts - 95 hCards marked up by Scott Reynen
- Jack L. Wolfgang II has converted the addresses in his resume to hCards.
- Mathieu Drouet and Annie Leger both have hCards
- Neil Dunn has published his rather good looking hCard
- Oliver Brown has published his hCard.
- Paradigm Productions published a vcard as a ul (marked up by Peter Jacobson)
- Patrick H. Lauke has marked up his contact info with hCard.
- Paul Schreiber has published his hCard on [http://paulschreiber.com/about/?contact his about page.
- Paul Schreiber's Sunnyvale House Concerts site publishes hCards for upcoming artists, as well as an hCard for the page itself. In addition the Past Shows page contains hCards for all past artists.
- Paul Smith has created an hCard page which is Human Readable, and a link to X2V passing the same hCard page to generate a vCard.
- Phil Windley has published his hCard.
- Piercarlo Slavazza has published an hCard.
- Rob Mientjes has published his hCard on his about page.
- Robert Bachmann has published his hCard and a button.
- Scott Reynen has published his hCard on [http://www.randomchaos.com/document.php?source=scott_reynen his profile page.
- StackFrame, LLC has published employee and general contact information as hCards.
- Steven Ametjan has published his hCard on his about page.
- Syndicate - Speaker List as a set of hCards
- TagCamp contact list
- Tantek's Thoughts includes an inline author hCard at the bottom of the page.
- Technorati's About page lists their Media Contact
- The Brothers McDowell have hCards at their Contact page.
- Twinsparc put an hCard in the header and footer of all their pages.
- Web 2.0 Conference speakers page marked up with hCard
- Web Essentials 05 marked up all their presenters with hCard.
Examples with some problems
- Gerard Braad has published an example on his profile page that is almost consistent with his original vCard file. Also progress is made for transforming his FoaF file to a hCard encoded representation. (also done for my spouse:Yong Yuan)
- (2005-09-27) PASSED, PASSED
- uses 'n given-name' and 'n family-name' instead of nesting the given- and family- names inside the 'n'
- has one 'tel' value with a bunch of values stuffed in
- probably more problems --RyanKing 17:19, 5 Jan 2006 (PST)
- Keri Henare has marked up his contact info page with hCard.
- (2005-09-27) PASSED
- (2005-11-01) hCard completely rewritten
- WARNING - type subproperty in classname
- Cori Schlegel discusses how he has updated his contact page with hCard
- INVALID - using 'prefix' instead of 'honorific-prefix' and type's in classnames (in both adr and tel) and has two photo's (the second could be 'logo') --RyanKing 15:15, 5 Jan 2006 (PST)
- The good ship Leonid Miloslavskiy spotted in the North Atlantic
- INVALID --RyanKing 00:50, 27 Oct 2005 (PDT)
- class="family" should probably be family-name
- the "n" property is missing and the "n" optimization can't be applied
- the first geo propery is empty, the second one is invalid (ie, it doesn't contain lat/long)
- INVALID --RyanKing 00:50, 27 Oct 2005 (PDT)
- Landsbanki Føroya
- INVALID - using embedded rdf/xml invalidly
- Chris Cherry's contact page with his hCard
- WARNING - uses class="cell" instead of <span class="type">cell</span>
- University of Bath Person Finder results are encoded with hCards so you can easily create a vCard from any result.
- Richi Jennings has put up his attempt
- INVALID, missing FN --RyanKing 12:47, 5 Jan 2006 (PST)
- shifting pixel photoblog has published an hCard.
- "organization_name" should be "organization-name" (s/_/-/), otherwise good --RyanKing 14:01, 5 Jan 2006 (PST)
This section is informative.
The following implementations have been developed which either generate or parse hCards. If you have an hCard 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.
- Tails is a Firefox Extension that will display the presence and details of microformats (hCard, hCalendar, hReview, xFolk) on a webpage.
- Smartzilla is a Firefox Extension that finds hCards on web pages and lets you add them to your addressbook.
- pnh_mf is a plugin for Textpattern that supports embedding hCard and other microformats in templates and blog posts. Written by Chris Casciano.
- There is evidence of built-in hCard support in the Konqueror browser. Specifically, Konqueror 3.5, in KDE 3.5 (kubuntu Breezy w/ update).
- There is evidence of a kwiki plugin for hCards. Update: the hCard kwiki plugin svn repository. See the documentation of the hCard kwiki plugin.
- X2V is a bookmarklet that parses hCard and produces a .vcf (vCard) stream. Note: needs to be updated as the spec is refined
- Duncan Walker has built a Firefox extension that gets hCard data from a webpage, uses Brian Suda's XSL (locally) to transform it to vcard format and opens the resulting .vcf file.
- George has written a Greasemonkey user script that detects hCards and allows users to easily add them to their address book application. Relies on the X2V web service to do the conversion.
- David Janes has written a greasemonkey script that finds many microformat elements, including hCards, and provides a popup menu of actions. The hCard to vCard conversion is done internally within the script. This does not work with FireFox 1.5+/GreaseMonkey 0.6.4+.
- Mark Pilgrim has also written an hCard parser Greasemonkey user script. It is self-contained and does not rely on the X2V web service.
- Oliver Brown has written an "extension" to SimpleXML that gives simple access to hCard information in PHP 5.
- Andrew D. Hume has built a system (Wordpress plugin?) for using hcards in your blog to represent people leaving comments on blog posts.
- The hCard creator is a very simple, yet illustrative, open source user interface / form / script which creates an hCard in real-time as you type in a set of contact information.
- rfc2629.xslt now attempts to generate hCard information (RFC2629 is an XML format for authoring RFCs and Internet Drafts, see example document)
- iChat buddy list to hCards - Open source AppleScript to automatically convert one's buddy list in the MacOSX iChat AIM client into a valid XHTML 1.0 Strict list of hCards.
- palmagent is a collection of palmpilot and sidekick tools. It includes X2V derivatives xhtml2hcard.xsl and toICal.xsl plus some hcardTest materials
- OpenPsa 2.x CRM application uses hCard for all person listings. The widget is reusable across Midgard CMS
- Emiliano Martínez Luque has written an experimental hCard finder and structured search application that finds hCards within a given set of URLs and returns the ones that match the specified search criteria.
This section is informative.
There are numerous potential additional uses and applications for hCards on the Web. The following are merely a few thoughts and possibilities that folks have come up with:
- As an open standard/format for Gravatars.
- Marking up individual authors of blog posts on a group blog
- Marking up people's names and URLs in a blogroll
- Any reference to people in blog posts (e.g. when citing them, or referencing them, or describing them, by name).
- HTML reformatted version of RFC2426
- hCard term introduced and defined on the Web, 20040930
- FOO Camp 2004 Simple Semantic Formats presentation, 20040910
- Contributed from http://developers.technorati.com/wiki/hCard.
- XHTML 1.1
Specifications That Use hCard
- hCard FAQ - If you have any questions about hCard, check here, and if you don't find answers, add your questions!
- hCard parsing - Normatively details of how to parse hCards.
- hCard issues - Please add any issues with the specification to the issues page.
- hCard profile - The XMDP profile for hCard
This specification is a work in progress. As additional aspects are discussed, understood, and written, they will be added. These thoughts, issues, and questions are kept in separate pages.
- hCard Brainstorming - where we are keeping our brainstorms and other explorations relating to hCard
- hCard tests - a wiki page with actual embedded hCards to try parsing.
- Digital Web Magazine: Microformats Primer by Garrett Dimon has a good intro to hCard
- Practical Microformats with hCard by Drew McLellan
- Andrew D. Hume has written a blog post on usable microformats which discusses hCard
- Jesse Skinner's introduction to hCard
- Shaun Shull's great post on How Microformats Affect SEO, including his hCard as an example.
- See also blogs discussing this page and the hCard tag