How to Record Frequency Changes

Changes in the frequency of issuance are common.  CONSER practice is to record all frequency changes in the bibliographic record with the current frequency recorded in the 310 and former frequencies in 321 fields beginning with the earliest to the latest. Capitalize the first word of each field but do not include a period at the end of any field. Update the Fixed-length field 008/18-19 with the current (new) frequency with every change in frequency.

310 ## Annual, $b 1983-

321 ## Monthly, $b Mar. 1972-Dec. 1980

321 ## Semiannual, $b 1981-1982

Subfield $b must be given in all 321 fields, and is used in field 310 when the date of current frequency is different from the beginning date of the publication and when a former frequency is given in field 321. 

If the serial has more than three past frequencies, you may give only the current frequency and use a "Frequency varies" note in field 321.

310 ## $a Annual, $b 1991-

321 ## $a Frequency varies, $b Aug. 1987-1990

Uncertain data (a known date that may not be the earliest or latest) is enclosed in angle brackets and may be suppressed from printing on output.

310 ## Annual, $b <1984->

321 ## Semiannual, $b 1976-<1982>

When inputting only an ending date, leave no spaces before the closing date, except for the space following the subfield code. If only a portion of the date is known, leave an appropriate number of spaces for the missing portion.

310 ## Semiannual, $b -1984

321 ## Annual, $b 198 –

321 ## Monthly, $b 19 –