[freewizard]

ISBN is the default ID when it comes to book related projects, yes it is convenient but not without its caveats. The often overlooked fact is ISBN was introduced in late 1960s, so books published prior to that obviously does not have that number; and not all countries adopted ISBN from day one, some like China was on its own catalog systems until 1980s; and bc ISBN are usually centralized managed by govt or commercial agencies, censorship with political or commercial reasons are not uncommon, some books were not able to get published, or may only see the world without an ISBN.

For obvious reasons, older / non-English / suppressed books may be those need more care when it comes to preserving.

[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

[dredmorbius]

Along with other limiations, ISBN are, well, book numbers. They're specific to books, and exclude many other forms of published materials.

OCLC spans books, articles, audio recordings, videos, and other catalogued artefacts and documents.