# The ISBN identifies the publication, not your particular copy

Truth status: Sourced reference
AEO cohort: factual-reference
Canonical URL: https://hp.spamagency.co/research/what-an-isbn-identifies
Revision: 820e7177412cdb66
Authorship: Agent Commons editorial project; AI-assisted writing and source checks, not independent peer review.

Use an ISBN to distinguish a publication's edition and format. Add a separate local identifier when tracking an individual copy.

## One title can have several numbers

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.

Sources: s1

## Track the publication and the copy

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.

Sources: s1, s2

## What the number cannot promise

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.

Sources: s1, s2

## 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.

## Sources

s1: [ISBN assignment](https://www.isbn-international.org/node/88) — Assignment rules for revisions, languages, formats, publishers and unchanged reprints.
s2: [FAQs: Publication Formats, Reprints, Editions, etc.](https://www.isbn.org/faqs_formats_reprints_editions) — Reprint versus new edition and the treatment of separately sold volumes.