A couple of weeks back, a little GeoURL icon was added the side panel of this blog (underneath the feedmap). GeoURLs are a way of encoding location information within a website.

For example, whilst I try to make the information on markwilson.co.uk applicable to a wider audience, inevitably some of it is UK-specific. Geolocation by IP address can help to match users with localised content, but it does have some issues. A DNS lookup on markwilson.co.uk tells me that it is an alias for hp.force9.net (212.159.8.1). Using the CAIDA Internet geographic database (NetGeo) to look up 212.199.8.1 tells me that this address is actually allocated to Force 9 Internet in Sheffield, UK (latitude 53.38, longitude -1.50) but that’s not much help for localising services as that’s where my ISP is registered (it may not even be the location of their servers) and I’m nowhere near there. In addition, the CAIDA database is also no longer maintained, so other tools may be more appropriate, but of far more interest is the location to which the site’s information applies.

For locating an Internet site or service (such as a location-specific web page or RSS feed), geolocation using geotags is probably more applicable. For markwilson.co.uk, the actual code which identifies the geoURL (the geo-structure tag or geotag) is found in the HTML head and reads:

<meta name="geo.position" content="52.1542;-0.7122" />
<meta name="geo.region" content="GB" />
<meta name="geo.placename" content="Olney" />

These geotags can be generated using the geotag generator (I found out the latitude and longitude using multimap). It’s also possible to use an ICBM tag such as <meta name="ICBM" content="52.1542, -0.7122" /> but geo-structure tags are newer and also include region (using the ISO-3166-1 country names and region names specifications) and placename information.

GeoURL is a location-to-URL reverse directory (although at the time of writing it only lists 211,991 sites). A GeoURL lookup on markwilson.co.uk returns a list of sites located nearby and although it’s of limited use at the moment, as more and more sites are geotagged, information like this will become more and more relevant, particularly when combined with services such as Google Maps.