CCM13.3. Frequency notes (Fields 310/321)

13.3.1. When to give (AACR2 12.7B1)
The current frequency is expressed in
Field 310 is optional in the CONSER core record but is mandatory for all LC core or full records.
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, CONSER catalogers 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. Other catalogers may omit the frequency note when information given elsewhere in the record is considered adequate. The frequency is also taking on an added importance with increased use of the MARC 21 holdings standard for creation of publication patterns.
13.3.2. Sources of information
The frequency is taken from information found in the piece or supplied by the publisher or from evidence of issues already published. If there is no stated frequency, give the probable frequency when there is sufficient evidence to indicate the publishing pattern. Do not use a question mark. If the frequency is unknown, omit field 310 and code the fixed field bytes as "u/u".
Sometimes the frequency requires further explanation to account for stated irregularities in the publishing pattern. Such information is generally taken from the piece but may also be supplied and is given in parentheses following the frequency.
310 ## $a Monthly (except July-Aug.)
310 ## $a Biweekly (Apr.-Sept.)
When cataloging with a run of a serial in hand, you may find that the actual publishing pattern varies considerably from the stated frequency. In general, give the stated frequency. In cases where it is obvious that the stated frequency is not the actual frequency, as evidenced by a number of issues and the numbering of those issues, give the actual frequency when it can be determined.
Stated frequency in piece:
Monthly
Evidence from issues over a 3 year period:
2 or 3 issues a year
310 ## $a Two or three issues a year
Fixed field: Freq = f / Regulr = x
13.3.3. Terminology
The list of frequencies in 008/18-19 does not include all possible frequencies. When a serial is issued according to a frequency not on the list, construct a frequency statement using terms such as "... no. a year" or "... issues a year."
310 ## $a Four no. a year
310 ## $a Four times a year
310 ## $a Four issues a year
"Four no." would imply that the serial is numbered; however, some numbers may be combined. "Four times" or "Four issues" indicates that there are four separate pieces received regardless of the numbering. This is based on the individual serial and is a matter of cataloger's judgment.
Note: Do not confuse the frequency with the designation system of the serial. For instance, Time is a weekly that has two volumes each year, each with its own internal numbering. The frequency is determined by the pattern of issuance of the issues, not their numbering.
When supplying parenthetical information, try to use the publisher's terminology when clear and succinct.
310 ## $a Biweekly (during the school year)
310 ## $a Semiweekly (May-Aug.)
If there is more than one frequency in a given year, the other frequencies are indicated in parentheses.
310 ## $a Monthly (bimonthly June-Sept.)
13.3.4. Designations and former frequencies
Field 321 is used for former frequencies. When this field is given, a designation must be also included in all of the frequency fields (310 and 321). As with other notes, dates are generally given but numbers may also be used. When the exact date range is unknown, give what is known in angle brackets. Do not give field 321 without field 310. Do not include a designation when only the current frequency is given in field 310 since it is assumed that this is the frequency for all issues beginning with the first. If the serial has changed its frequency many times, you may give only the current frequency and use a "Frequency varies" note in field 321. For more information, see CEG 310/321.
310 ## $a Monthly, $b Aug. 1976-
321 ## $a Bimonthly, $b June 1, 1967-July 15, 1976
310 ## $a Annual, $b 1991-
321 ## $a Frequency varies, $b Aug. 1987-1990