Differences Between the 2024 and 2025 Editions

The purpose of this field is to provide a list of terms representing frequently requested merchandising themes and topics so that various organizations within the book industry can assemble materials appropriate to that theme or topic.

Merchandising themes can be used in addition to subject codes to denote:

• An audience to which a work may be of particular appeal.
• A time of year or event for which a work may be especially appropriate.
• A frequently requested topic.

Note that this is an optional field, separate from the subject field – although related, subject codes and theme codes should not be placed in the same field.

In addition to grouping together works that can be classified under a variety of subjects, this field can be used to further describe fictional works that have been subject-coded by genre.

Trans key:    A = Addition    C = Change