Serial editions are defined as:

separate complete serials that are issued simultaneously, usually with the same title, and that are intended for a specific audience. (CCM)

Aside from language editions, serial editions may differ due to geographical coverage (e.g., North American edition), scope (e.g., teacher/student editions), or format (e.g., large-print edition). The records for the editions may or may not have an edition statement in the 250 field. Each edition is linked to the other editions with a 775 linking note. Example:

If there is more than one related edition, field 580 maybe used to provide a single note. Give each title also in a separate 775 field with first indicator tagged "1."

See also:

14.3. Horizontal relationships