We are currently using an outdated OPDS 1.x + ODL Feedbooks/DPLA feed, ("legacy" below). It has some problems and I'm not sure how well-maintained it is at this point.

Th legacy OPDS 1.x feed: https://www.feedbooks.com/harvest/odl uses Atom entry id as identifier

We need to move the new OPDS 1.x feed:

• New OPDS 1.x: https://market.feedbooks.com/api/libraries/harvest.atom
• Use publication identifier (dcterms:identifier), but could fall back to Atom entry id
• Can also request via content negotiation.
• The publication identifier should take precedence over the Atom ID