Though the MARC Format for Holdings Data may be used for all bibliographic items, the CONSER Patterns and Holdings Project deals with serials only. All successive entry records for currently published serials (S/L=0,Dtst=c) in the OCLC database (including new records) are within scope for the project.
Consider current serials in the CONSER database (containing field 042 lc, lcd, nsdp or msc) as the project's highest priority. Serials of national or international importance are of special interest, because their data can be used in serials checkin systems by the widest selection of libraries. Data for other current serials (non-CONSER data, data for local serials) is of lower priority but may be input. Data for ceased serials should not be input at this time.
When a current serial ceases, do not remove caption and pattern information from its record. If you know that the captions and pattern given have persisted throughout the life of the serial, you may close off the holdings statement. See Section 220.127.116.11.
The current captions and the current publication pattern (field 853), and the holdings statement (field 863) corresponding to the current captions and pattern, should have priority. Changes in captions and patterns should be examined to see whether the changes warrant a new pattern field and associated holdings, or are too minor to be regarded for the project. See Section 3.3, "When to input a new caption/pattern field".
Older captions and superseded patterns, while still useful, have a lower priority for input. The Task Group is examining options for handling older caption and pattern data.
Because of space limitations in CONSER records, generally include only captions and patterns for basic bibliographic units (i.e., those coded in MFHD as 853/863) in 891 fields.
Optionally: If it is necessary to display information about an important supplement or cumulative index which appears on a regular, scheduled basis, and there is room in the record, 891 fields with subfields $9 854, 855, 864, or 865 may be included.
In order to maximize usefulness of this data, the project must monitor currently published serials for changes in caption and pattern data; such a change requires input of new 891 fields for the new caption/pattern and the holdings statement corresponding to it. Rapid updating of caption/pattern data within bibliographic records, if conscientiously performed, would inspire reliance on the CONSER database as a source of serials control information for the records within it. In order to keep the bibliographic information in sync with the pattern data, changes to 891 fields may also necessitate changes to frequency, regularity, and enumeration/chronology data in the body of the record.
The OCLC Cataloging Subsystem reserves for local holdings output fields 853-855, 863-865, and 866-868 , which would ordinarily be used for input of captions/patterns and holdings data. Therefore, OCLC field 891 has been defined to contain the holdings data for this CONSER project. Within the OCLC record, the tag is always the same regardless of the data content; but within the field, a subfield $9 carries the tag actually intended for MARC holdings output. The indicators of the 891 field become the indicators of the destination tag when it is output via programming to a MARC holdings record or a MARC-based serials control program. Each new pattern requires a pair of fields tagged 891, the first with a subfield $9 85X, the second with $9 86X. See Section 3.2.3.
OCLC has now removed most 510 fields from serial records in the database, so the instructions formerly given in this section are no longer needed. See the announcement on the CONSER web page. For further considerations on record length, see Section 4.2.