5. Application of ISBN

5.1. General

A separate ISBN must be assigned to every title, or edition of a title by each publisher, but NOT to an unchanged impression or unchanged reprint of the same title in the same format by the same publisher. Revised editions require a new ISBN. A price change does not call for a new ISBN. Changes of the format induce a new ISBN. The same title being published in a series and individually is treated as two different editions.

5.2. Facsimile reprints

A separate ISBN must be assigned to a facsimile reprint produced by a different publisher.

5.3. Books in different format

A separate ISBN must be assigned to the different formats in which a particular title is published i.e. paper, cloth, braille, microfilm, microcomputer software of the same title, each receive a separate ISBN.

5.4. Loose-leaf publications

If a publication appears in loose-leaf form an ISBN is assigned to identify an edition at a given time. Individual issues of additions or replacement sheets will also be given an ISBN, when they are separately stocked.

5.5. Multi-volume works

An ISBN must be assigned to the whole set of volumes of a multi-volume work; also, if individual volumes of the set are sold separately, each volume must be assigned its own ISBN. Thus the individual processing and sale of single volumes is made possible. Even when multi-volume works are only sold as a set, the assignment of ISBN to each volume is advisable: It facilitates the handling of returns (damaged volumes) and the processing of shipments when not all volumes are published or distributed at the same time.

5.6. Backlist

A publisher is required to number all backlist publications and publish the ISBNs in catalogues. The ISBN must also be printed in the first available reprint of a backlist title.

5.7. Collaborative publications

A publication issued as a co-edition or joint imprint with other publishers is assigned an ISBN by the publisher in charge of distribution. Other co-publishers may assign their ISBNs if they want to.

5.8. Books sold or distributed by agents

(Except for a) this applies only to countries that are not yet participating in the system)

1. As the ISBN standard states, a particular edition, published by a particular publisher, receives only one ISBN. This ISBN must be retained no matter where, or by whom, the book is distributed or sold.
2. A book imported by an exclusive distributor or sole agent from an area which is not in the ISBN system and which has no ISBNs assigned to it, may be assigned an ISBN by the exclusive distributor.
3. Books imported by an exclusive distributor or sole agent to which a new title page, bearing the imprint of the exclusive distributor, has been added in place of the title page of the original publisher, are to be given a new ISBN by the exclusive distributor or sole agent. The ISBN of the original publisher should also be given.
4. A book imported by several distributors from an area not in the ISBN system and which has no ISBNs assigned to it, may be assigned an ISBN by the group agency responsible for those distributors.

5.9. Acquisition of one publisher by another

A publisher acquiring another publishing house must continue to use the originally assigned ISBN until the book is reprinted under the new company imprint.

5.10. Acquisition of complete stock of a publisher

A publisher acquiring the complete stock of another company must use the original publisher's assigned ISBN until the new company reprints under its own imprint.

5.11. Publishers with more than one place of publication

1. A publisher operating in several places which are listed together in the imprint of the book will assign only one ISBN to the book.
2. A publisher operating separate and distinct offices or branches in different places may have a publisher identifier for each office or branch. However, each book published is to be assigned only one ISBN. This ISBN should be assigned by the office or branch responsible for publication.

5.12. Register of ISBN

It is the responsibility of all publishers to inform their group agency or the organization responsible for the maintenance of title registration of the ISBNs that have been assigned to published and forthcoming books. When the publisher does not take this responsibility, the group agency or the organization responsible for the maintenance of title registration is authorized to maintain the ISBN register of this publisher on its own initiative.

5.13. ISBN can never be re-used

An ISBN, once assigned, can never be re-used, under any circumstances. This is of the utmost importance to avoid confusion.
If, through a clerical error, a number is incorrectly assigned, the number must be deleted from the list of useable numbers and must never be assigned to another title.
Publishers should advise the group agency of the number(s) deleted and of the titles to which they were erroneously assigned.