An ‘encoding scheme’ for populating the e-GMS Subject element of metadata. It is fully compliant with ISO 2788 and BS 8723, the International and British Standards for monolingual thesauri. The vocabulary was developed with the backing of the ODPM and now belongs to the Cabinet Office’s e-government unit.
I guess would form the basis of subject categorisation in any UK public e-participation project. Though there seem to be a few other schemas out there.
On the other hand as Simon Dickson has pointed out a couple of times, the IPSV has pretty low credibility amongst local government web managers, so any mention of IPSV is as likely to be a hindrance as a help