Geo (microformat)

Geo is a microformat used for marking up geographical coordinates (latitude and longitude) in HTML (or XHTML).[1] Coordinates are expected in angular units of degrees and geodetic datum WGS84.[1] Although termed a "draft" specification, the format is a de facto standard, stable and in widespread use;[2] not least as a sub-set of the published hCalendar[3] and hCard[4] microformat specifications, neither of which is still a draft.[3][4]

A Geo microformat, detected on the Wikipedia page for Great Barr, by Firefox's Operator extension. Users may add alternative mapping sources to those shown, which are included by default.

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 web mapping tool, or to load them into a GPS device, index or aggregate them, or convert them into an alternative format.

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.[note 1]

The Geo microformat is applied using three HTML classes. For example, the marked-up text:

<div>Belvide: 52.686; -2.193</div>

becomes:

<div class="geo">Belvide: <span class="latitude">52.686</span>; <span class="longitude">-2.193</span></div>

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.

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 proposals, none mutually-exclusive, to extend the geo microformat:

  • geo-extension - for representing coordinates on other planets, moons etc., and with non-WGS84 schema
  • geo-elevation - for representing altitude
  • geo-waypoint - for representing routes and boundaries, using waypoints

Users

Organisations and websites using Geo include:

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

h-geo

An alternative to Geo, h-geo, has been proposed. This is applied using three HTML classes. For example:

<div class="h-geo">Belvide: <span class="p-latitude">52.686</span>; <span class="p-longitude">-2.193</span>; <span class="p-altitude">120</span></div>

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

See also
  • GeoSPARQL, Geographic Information System (GIS) data for the W3C Semantic Web using the Resource Description Framework (RDF) and SPARQL
  • Geo URI specified in RFC 5870
  • ISO 6709
  • ICBM address, an older geotagging format
  • Schema.org, web standard schema.org/geo.

Notes
  1. Must and should are used per the IETF document RFC 2119

References
  1. "Geo Spec". microformats community. Retrieved 17 August 2010.
  2. "Extending HTML5 — Microformats". HTML5 Doctor. Retrieved 19 August 2010.
  3. "hCalendar 1.0 Spec". Microformats community. Retrieved 17 August 2010.
  4. "hCard 1.0 Spec". Microformats Community. Retrieved 17 August 2010.
  5. "Microformats in Google Maps". Retrieved 30 April 2016.
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