Books (monographs) published within a series and annual / biennial publications are eligible for both ISBN and ISSN assignment.

An ISBN identifies an individual book in a series, or a specific year for an annual or biennial, and a different ISBN is used for every book.

An ISSN identifies the title of the monographic series, or the ongoing annual or biennial, and the same ISSN is displayed on every book published within that series as long as the series title remains unchanged. The series title must be clearly and explicitly stated on each book, for example, on the front or back cover, on the title page, or on the editorial page, in order to be eligible for an ISSN.