Identifying Codes

Please add any identifying codes on your comic or book.

This is one of the most important fields on the submission form as they are key in differentiating one version from another.

Identifying code is not a required field as not all items have one, but we strongly encourage you to add any and all identifying codes if your comic or book does have them.


International Article Number - also known as the European Article Number. Generally 13 digits long, but has been adapted to different lengths to accomodate smaller packaging sizes.

ISBN (International Standard Book Number)

A unique book identifying number. Introduced in 1970 it has been published as international standard ISO 2108.

ISSN (International Standard Serial Number)

A unique identifying number for a serial publication. Introduced in 1975 it has been published as international standard ISO 2108.

Library of Congress Catalog Card Number (LCCN)

Should only be added if printed inside the book, usually on the verso of the title page. More info here.

SBN (Standard Book Numbering)

A 9 digit unique book identifying number, introduced in 1966 and discontinued in 1974.


Universal Product Code widely used in the United States, Canada, United Kingdom, Australia, New Zealand, in Europe and other countries. Usually a 12 digits barcode.