Collection descriptions might describe anything that was a group of physical or digital things. My original viewpoint is from library and information science, but I believe the notion of a collection description could be used in other disciplines http://www.selfdescription.org - Tim Hodson
Existing metadata schema
Dublin Core are working on a collection description application profile which is nearing completion. DC CD AP
Naturally the DC CD AP specifies metadata that should be in a collection description, and the metadata sets are used by the IESR, SCONE, Archives Hub, (all with other local data) but noticeably, not your average library or museum.
A collection description re-modelled as a microformat would allow collections to be discoverable on any library website suitably marked-up, thus opening up an organisation's collections to a wider audience.
A 3 month investigation into the possibilities and some background survey work was carried out, and results of which can be read in a pdf. Self-Description-Tim-Hodson-Msc.pdf