4.3. Publication types
Document identification and classification is governed at international level by different agreements and standards, most notably the following:
https://www.iso.org/standard/72642.html
https://www.iso.org/standard/59743.html
https://www.iso.org/standard/65483.html
https://www.isbn-international.org
https://www.iso.org/standard/73846.html
https://www.ifla.org/files/assets/cataloguing/isbd/isbd-cons_2007-en.pdf

(https://www.iso.org/members.html).
According to these standards and agreements, publications can be divided into two major categories: monographs and continuing resources.
4.3.1. Monographs
Pursuant to ISO 2108:2017 (ISBN), monographs are non-serial publications that may be complete in one volume or intended to be complete in a limited number of separate volumes, that may or may not be published simultaneously and that are made available to the public in any product format (hardback, paperback, audiobook on cassette, CD, DVD, Braille book, website, electronic book, etc.).
Monographs in several volumes consist of a predetermined number of physically separate parts (separate volumes), with the exception of publications in instalments. They are intended to form or are published as a complete work. The separate parts may have their own titles and statements of responsibility.
Each monograph is identified by an international standard book number (ISBN) (see Section 4.4.1).
4.3.2. Continuing resources
Pursuant to ISO 3297:2020 (ISSN), continuing resources are works made available to the public in any media format as successive or integrated issues that generally carry a numerical order or chronological indication, and that do not have a predetermined publication duration. Continuing resources include:
Each continuing resource is identified by an international standard serial number (ISSN) (see Section 4.4.2).
4.3.3. Combined serial publications and monographs
Some serial publications, such as yearbooks and monographic collections, can also be considered as monographs for certain purposes, such as marketing. It must be possible to purchase them either individually or through a subscription.
These publications must be considered first and foremost as serial publications and be assigned an ISSN. They are then assigned an ISBN as monographs.