[wiml]

A second issue is that ISBNs identify a specific SKU (different formats will have different ISBNs, different printings may even get different ISBNs, etc), but book-related projects typically want some way to identify "the same book" across all these different formats, printings, sometimes even editions and translations and collections. OCLC IDs are identifying a different space than ISBNs are.

[Tomte]

The biggest problem of all is that there are many ISBNs that have been reused for either a later edition of "the same" book or for a totally different book, which should never happen.

Sometimes it is because people are sloppy, sometimes people try to save a little money (because ISBNs cost money).

[raybb]

What you're referring to is sometimes referred to as a "work" vs "edition"

https://openlibrary.org/help/faq/editing#work-edition

[ahi]

It gets much much more complicated than that. There are never ending discussions about FRBR: Functional Requirements for Bibliographic Records. https://www.ifla.org/references/best-practice-for-national-b...

* Work is defined as the intellectual or artistic content of a distinct creation. It refers to a very abstract idea of a creation e.g. Shakespeare’s Romeo and Juliet and not a specific expression.

* Expression is the intellectual or artistic realization of a work. The realization may take the form of text, sound, image, object, movement, etc., or any combination of such forms.

* Manifestation is the embodiment of an expression of a work. For example a particular edition of a book or a specific music recording.

* Item is a single exemplar of a manifestation. Cataloguing is generally done, based on an item directly available to a cataloguer