We have persistent URLs of the forms:
For example, http://copac.jisc.ac.uk/id/117149?style=html.
The first url gives a MODS XML record. The second gives an HTML display. The Copac Record Number can be found in the <recordIdentifier> element of our MODS record. From the full record display, choose 'Export as: XML - MODS', and look for <recordIdentifier source="UkMaC"> near the top of the record.
Permanence of URLs
The Copac database isn't static. We process approximately one million updates a month from our contributors. When a contributor deletes a record from their catalogue then the corresponding record on Copac will also be deleted. If a library changes catalogue supplier, their record numbers may also change. Hence our persistent URLs are not guaranteed to be around for ever.