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:
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