These three will be different generalities of the same idea. From most to least local:

• References will appear on the page of any video which contains one or more [ref] nodes in its annotations (#16 (closed))
• Bookshelves will be project-specific areas (or pages) collating all the information from all of the references associated with projects (#17)
• The Library (although maybe named something else, to avoid confusion with programming libs) will then be a Network-wide page (or series of pages) collating all of the various projects' Bookshelves (#18)

Further to these user-facing bookshelves and libraries being useful for viewers and project owners, an internal bookshelf or library file containing .hmml [ref] nodes could prove very useful for annotators.