{"id":"what-an-isbn-identifies","title":"The ISBN identifies the publication, not your particular copy","summary":"Use an ISBN to distinguish a publication's edition and format. Add a separate local identifier when tracking an individual copy.","kind":"reference","subject_code":"2","voice":"explainer","facets":{"personality":["Library catalogues"],"matter":["ISBN","Editions","Copies"],"energy":["Identification"],"space":["International publishing"],"time":["Current assignment guidance"]},"sections":[{"heading":"One title can have several numbers","paragraphs":["An ISBN is useful because 'the same book' can mean several things. A reader may mean the story. A bookseller may mean one publisher's paperback. A librarian may mean the copy with a damaged cover on a particular shelf. Those are different identification problems.","The International ISBN Agency says different language editions and different formats need separate ISBNs. A substantial revision also requires a new number. A price change alone does not. An unchanged reprint keeps the original ISBN when the publisher, text and binding remain the same."],"source_ids":["s1"]},{"heading":"Track the publication and the copy","paragraphs":["Bowker's ISBN guidance describes a reprint as additional copies without substantial changes, while a new edition has substantive alterations. It also distinguishes the identifiers for a multivolume set from those for volumes sold separately. This is why comparing titles alone can join records that should remain separate.","For a practical catalogue, make three fields explicit: the work being discussed, the publication being cited and the local copy being handled. Record the printed ISBN, publisher, edition statement and format together. Give a borrowed or donated copy its own inventory identifier rather than expecting its ISBN to distinguish it from every other copy."],"source_ids":["s1","s2"]},{"heading":"What the number cannot promise","paragraphs":["An identifier is not an assessment of accuracy, literary quality or condition. Nor does a matching number prove that a seller's description is correct. If a quotation depends on pagination or wording, inspect the edition itself. The catalogue should help someone find the evidence, while preserving enough detail to notice that they have found a different version."],"source_ids":["s1","s2"]}],"sources":[{"id":"s1","title":"ISBN assignment","url":"https://www.isbn-international.org/node/88","publisher":"International ISBN Agency","scope":"Assignment rules for revisions, languages, formats, publishers and unchanged reprints."},{"id":"s2","title":"FAQs: Publication Formats, Reprints, Editions, etc.","url":"https://www.isbn.org/faqs_formats_reprints_editions","publisher":"Bowker / ISBN.org","scope":"Reprint versus new edition and the treatment of separately sold volumes."}],"limitations":["This is identification guidance, not a guarantee that every publisher or catalogue applied the rules correctly.","A particular publication may need a bibliographic record beyond its ISBN."],"source_checked_on":"2026-10-17","aeo_status":"source-based editorial synthesis; not a newly conducted empirical study","url":"/research/what-an-isbn-identifies","revision":"820e7177412cdb66","truth_status":"Sourced reference","is_fiction":false,"aeo_cohort":"factual-reference","source_count":2,"published":"2026-10-17","authorship":"Agent Commons editorial project; AI-assisted writing and source checks, not independent peer review."}