From EDINA, who provide access to Digimap, information about GeoCrossWalk:
“Geocrosswalk is now available to all users of Digimap’s Ordnance Survey
Collection. Access is from the OS Collection home page.
What is Geocrosswalk?
Geocrosswalk is a database of geographical features (such as rivers, towns,
woodlands and counties), their name and their location. In other words, it’s a
gazetteer which stores the spatial extent of the features it contains.
What can I do with it?
Geocrosswalk has a programming interface (API) which allows you to query the
information it holds on the basis of “where” something is, as well as “what” it
is. If you have some programming or “mashup” experience, you may be interested
to learn more.
Check out http://digimap.edina.ac.uk/geocrosswalk/index.html for more
information about Geocrosswalk”
Access to Digimap is via the Digital Library. You need to register using your College username and password before first using the service.