Geo

This document represents a draft microformat specification. Although drafts are somewhat mature in the development process, the stability of this document cannot be guaranteed, and implementers should be prepared to keep abreast of future developments and changes. Watch this wiki page, or follow discussions on the microformats IRC channel to stay up-to-date. Per the public domain release on my user page , this specification is released into the public domain. Public Domain Contribution Requirement . Since the author(s) released this work into the public domain, in order to maintain this work's public domain status, all contributors to this page agree to release their contributions to this page to the public domain as well. Contributors may indicate their agreement by adding the public domain release template to their user page per the Voluntary Public Domain Declarations instructions . Unreleased contributions may be reverted/removed. Thanks to everyone who participated in the Geo Microformat BOF at O'Reilly's Where 2.0 conference , and in particular to Nat Torkington and Vee McMillen of O'Reilly for arranging and hosting the BOF . Thanks to Chris Hibbbert for providing the real world geo-caching example . The vCard standard (RFC2426 ), has been broadly and interoperably implemented (e.g. Apple's Address Book application). The hCard microformat has similarly received significant adoption, from numerous sites publishing the format, to hCard to vCard proxies, to clientside javascript parsers. At the Where 2.0 conference in June 2005, there was widespread recognition that the community needed a way to simply and easily publish visible, extractable, geographic location information on the Web, given how often bloggers, and numerous other sites publish such information. The geo microformat BOF discussed this very topic, and concluded with a consensus decision to just try using geo from vCard/hCard. This specification introduces the geo microformat, which is a 1:1 representation of the aforementioned geo property from the vCard standard, by simply reusing the geo property and sub-properties as-is from the hCard microformat. Publishers can both embed geo addresses directly in their web pages and feeds, as well as markup existing latitude/longitude coordinates in the context of the rest of the information in their web pages and feeds. If the publisher knows and is publishing the name of the location in addition to its geo lat/long, then the publisher MUST use hCard instead of just geo to publish the name and geo lat/long of the location. If the publisher knows and is publishing the address of the location, OR if the address of the location was what was actually entered by a human, and the publisher simply turned that into lat/long using some sort of a service, then the publisher SHOULD use adr to publish the actual human entered address information since that communicates far more semantic information than a simple geo lat/long coordinate. 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. 1. 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. 1. For types with multiple components, use nested elements with class names equivalent to the names of the components. 2. Plural components are made sing