When there is no series numbering it may be difficult to distinguish between a serial issued in an unnumbered series and a common title/section title. According to LCRI 12.1B4, treat as a common title/section title when: 1) the more comprehensive title is found on related serials issued by the same publisher or 2) the word or phrase that would constitute the section title is dependent on the more comprehensive title and would not stand well alone. This decision is not always clear cut and the decision will depend to a great extent on knowledge of other publications as well as the form in which the word or phrase appears on the piece being cataloged.

See also:

12.6. Changes and other problems