“geo:” and vCards

June 10th, 2010 by alex Leave a reply »

vCard – the first spec to use “geo:”?

The first specification that is using the “geo:” scheme seems to be the revision of the vCard format. vCards are “virtual business cards”, and contain a multitude of contact information about a person or an organization.

vCard GEO property

The geographic location of a person’s office is of course one of those properties – even the original specification of vCard (RFC 2426) contained an “GEO” property (defined in Section 3.4.2). That property has a range of shortcomings:

  • There’s no way to specify altitude
  • the Coordinate Reference System is not defined (see here [PDF] why you should care)
  • Recommends to always use six decimal places (roughly one meter) rather than allowing for uncertainty values

New revision of vCard includes “geo:” URI

The current revision of the vCard specification (currently worked on in the IETF’s VCARDDAV working group) has changed the format of the “GEO” property. The new definition requires a URI rather than the lat/lon tupel as value, and notes in an example that the “geo:” URI scheme is “particularly well-suited”, although other URI schemes are allowed too. A example vCard using the “geo:” URI looks like this (edited for brevity):

FN:Simon Perreault

As outlined above, the structure of vCards allows to supply parameters for properties – in the example above, the GEO property is specified for the “work” location of the contact.

vCard applications become geo: aware

The integration of the URI scheme into the very popular vCard format means that very likely future revisions of vCard applications will be able to parse and use “geo:” URIs. Looking at the list of applications that support vCards, it looks like a bright future for our newly-born URI scheme.



  1. Andy Mabbett says:

    …and will the hCard/ Geo microformats:



    both based on vCard, follow suit?

  2. Andy Mabbett says:

    Although geo URIs can specify non-WGS84 coordinates reference systems (once defined), including those for off-Earth bodies, there is no equivalent field in the ADR (address), so the former will, but the latter will not, be usable to refer to locations on, say, the Moon.

  3. Alex says:

    Note that the GEOPRIV working group has not specifically endorsed “off earth” CRSes – their scope is definitely “on-earth”.

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