The current frequency is expressed in field 310 and also in fixed field 008/18 "FREQ." The regularity of issuance is expressed in fixed field 008/19 "REGULR" and sometimes in qualifying information added to field 310 or 321. If the frequency has changed, the former frequency(ies) is given in field 321. For instructions on input, see CEG 310/321. For a list of the appropriate terms to be used, see CEG 008/18.

When known, give the current frequency in all cases, even when the frequency is already contained in the title (LCRI 12.7B1). This policy was set for the benefit of reference librarians who requested eye-readable information in the record. It is easier to give the frequency in all cases than to decide when it could be omitted.

See also:

13.3. Frequency notes (fields 310/321)