CCM13.4. See also Module 8. Designations. Numbering peculiarities notes (Field 515)

13.4.1. When to give (AACR2 12.7B10)
The numbering peculiarities note is used to explain changes, irregularities, or complex situations relating to the numbering. Based on the importance of the information, decide whether to give a specific note that cites particular issues, whether to give a general note, or whether to omit the note altogether. If numbering deviations are numerous, consider giving a note such as "Some numbers issued out of chronological order," or "Some issues combined."
13.4.2. Uses
Field 515 is used to explain a situation that cannot be fully expressed in fields 362 and/or the 500 "Description based on" note. Examples of such use are:
• To explain changes in the numbering that don't require a new record and that don't constitute a new system of numbering (see Module 8)
• To explain the presence of multiple chronological designations when only one is given in field 362
• To cite numbering and publication sequences that are not the same (e.g., no. 1 has a later publication date than no. 2)
Field 515 is also used for:
• Report year or fiscal year coverage when the year does not end with December 31st and this fact is not evident from information given in other areas of the record
• Suspensions of publication, when known. There is no limit to the number of years that constitute a suspension. The numbering may resume or start over from no. 1.
• Serials issued in parts - when an issue of a serial appears in more than one physical volume
• Later issues lacking numbering
500 ## $a Description based on: 1995/1996. (only issue with designation)
500 ## $a Latest issue consulted: [2001?] (date of production)
515 ## $a Some issues lack designation.