PUID

PUID (PRONOM Persistent Unique Identifier) is an extensible scheme for providing persistent, unique and unambiguous identifiers for records in the PRONOM registry. The assignment of new PUIDs is managed by The National Archives (UK).

Example: fmt/42 which can be resolved as http://www.nationalarchives.gov.uk/PRONOM/fmt/42 to a summary page for the format in PRONOM