The simplest OPDS Catalog can be a single Acquisition Feed, so I'm
inclined to leave it.
"""
OPDS Catalog Root - The Atom Feed that represents either the complete
OPDS Catalog (a single Acquisition Feed) or the Atom Feed that starts
a set of Navigation Feeds. External links to the OPDS Catalog SHOULD
referenc e the OPDS Catalog Root Resource.
"""
Ah, I'd argue that the user's bookshelf is a totally separate thing, I
suppose it depends on the context. If the OPDS Catalog is All of Our
Users' Public Bookshelves, each bookshelf would be a part of that OPDS
Catalog. If I'm browsing the O'Reilly Media OPDS Catalog, the
bookshelf link would be to my private OPDS Catalog, which (could) be a
complete OPDS Catalog. Ditto an Ibis Reader bookshelf link from inside
HTML (speculative).