...
For volumes made up of previously published materials reissued by a publisher, usually with a collective title page but not always (often referred to as nonce collections), create a single bibliographic record for the collection (with a contents note). Curatorial requests to create individual analytical records should be discussed with the Head of Rare Book Section.
For groups of separately-published works gathered together for collective issue by a bookseller/publisher, with or without a title page (often referred to as nonce collections), use cataloger’s judgment to decide whether to create a single bibliographic record for the collection (preferably with a contents note), or to create in addition an analytical record for each item in the collection.
...