Geo (microformat)

Geo is a microformat used for marking up WGS84 geographical coordinates (latitude;longitude) in (X)HTML. Although termed a "draft" specification, this is a formality, and the format is stable and in use; not least as a sub-set of the published hCalendar and hCard microformat specifications.

Use of Geo allows parsing tools (for example other websites, or Firefox's Operator extension) to extract the locations, and display them using some other website or mapping tool, or to load them into a GPS device, index or aggregate them, or convert them into an alternative format.

Version 3 of the Firefox browser is expected to include native support for microformats [cite web | url=http://ejohn.org/blog/microformats-in-firefox-3/ | title=Microformats in Firefox 3 | last=Resig | first=John | date=2007-02-01 | accessdate=2007-03-25] , including Geo.

Usage

*If latitude is present, so must be longitude, and vice versa.
*The same number of decimal places should be used in each value, including trailing zeroes. ["Must" and "should" are used per the IETF document [http://www.ietf.org/rfc/rfc2119.txt RFC 2119] )]

There are two ways to convert ordinary (X)HTML into a geo microformat:

Three classes

Adding three classes. For example the marked-up text:

Belvide: 52.686; -2.193

becomes:

Belvide: 52.686; -2.193

by adding the class-attribute values "geo", "latitude" and "longitude".

This will display

Belvide: 52.686; -2.193

and a geo microformat for that location, Belvide Reservoir, which will be detected, on this page, by microformat parsing tools.

One class

In some cases, a shorthand version may be used, with just the outer class. Latitude must be first:

Belvide Reservoir is at 52.686; -2.193.

becomes:

Belvide Reservoir is at 52.686; -2.193.

Note that the separator must be a semi-colon (;). If the display of some other separator is desired, then the abbr element can be used, with the value to be interpreted placed in its title attribute:

Belvide Reservoir is at 52.686, -2.193.

This can also be used to display the location using some other schema:

Belvide Reservoir is at Grid reference SJ870099.

However, it is considered bad practice to use abbr to hide the location completely:

Belvide Reservoir is nice to visit.

Accessibility concerns

Concerns have been expressed [ [http://www.webstandards.org/2007/04/27/haccessibility/ Web Standards Project, hAccessibility: Abbreviations in Microformats] ] that the use of the abbr element (using the so-called [http://microformats.org/wiki/abbr-design-pattern abbr-design-pattern] ) in the above manner causes accessibility problems, not least for users of screen readers and aural browsers. Work is underway to find an alternative method of presenting coordinates [ [http://microformats.org/wiki/assistive-technology Microformats Wiki: Assistive Technology] ] .

hCard

Each Geo microformat may be wrapped in an hCard microformat, allowing for the inclusion of personal, organisational or venue names, postal addresses, telephone contacts, URLs, pictures, etc.

Extensions

There are three active proposals, none mutually-exclusive, to extend the geo microformat:
* [http://microformats.org/wiki/geo-extension-strawman geo-extension] - for representing coordinates on other planets, moons etc., and with non-WSG84 schema
* [http://microformats.org/wiki/geo-elevation-examples geo-elevation] - for representing altitude
* [http://microformats.org/wiki/geo-waypoint-examples geo-waypoint] - for representing routes and boundaries, using waypoints

Users

Organisations and websites using Geo include:

*Flickr - on over 3 million photo pages
*Geograph British Isles - on 350,000+ photo pages
*Multimap - all map pages
*MyMap - example: [http://mymap.yam.com/place/point/charleschuang/6695/] (Taiwanese language site)
*OpenStreetMap - wiki pages about places, GPS traces and diary entries
*The West Midland Bird Club
* [http://www.locify.com Locify] - location enhanced browsing on mobile phone
*Wikipedia - embedded in geo templates of map-link pages
**German Wikipedia - ditto
**Dutch Wikipedia - ditto
**Swedish Wikipedia - ditto
**Italian Wikipedia
*Wikitravel

Many of the organisations publishing hCard include a geo as part of that.

References

ee also

* ICBM address
* LOC record

External links

* [http://microformats.org/wiki/geo Geo spec] with notes and examples
* [http://microformats.org/wiki/geo-cheatsheet Geo cheat-sheet] a quick reference