If you have an interested in permanent identifiers, you might also be interested the archival resource key standard https://wiki.ucop.edu/display/Curation/ARK h

If you have an interested in permanent identifiers, you might also be interested the archival resource key standard https://wiki.ucop.edu/display/Curation/ARK https://wiki.ucop.edu/display/Curation/ARK and the EZID service http://n2t.net/ezid/ http://n2t.net/ezid/ . Disclaimer, I work at the same digital library where the standard and the service are developed and maintained.