Template:geo-note

• Coordinates MUST use the datum of WGS84.
• If latitude is present, so MUST be longitude, and vice versa.
• Coordinates MAY be combined a single <abbr> element; then the latitude and longitude MUST be separated by a semicolon in the title attribute and latitude MUST be first:

<abbr class="geo" title="37.386013;-122.082932">home</abbr>

• Best practice is that the same number of decimal places SHOULD be used in each value, with trailing zeroes if applicable.
• Some sources for latitude/ longitude coordinates