Whenever a standard book number (ISBN or SBN) or standard serial number (ISSN) appears on an item or its accompanying material, the number is always included in the bibliographic record. (3)

Periods are not inserted into this data, either in association with the initials, or at the end of the data. Example:

The resultant number should always contain ten digits, or, in some cases, nine digits and an X as the final, check-digit character, however, the number is transcribed as it appears on the item even if it contains fewer than ten characters.

Map Series/Set:

When each sheet of a map series/set, serial (4) map, or a multi-sheet single map has its own ISBN number, the ISBN fields (tag 020) may generally be omitted if there are more than three sheets.

Accompanying Material:

When a map and its accompanying material each have a separate ISBN, transcribe each number in a separate ISBN field (tag 020). Qualify the ISBN for the accompanying material with an appropriate term. Example:

See also:

Numbers