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Brief guidelines for editing and replacing WorldCat records

For Expert Community members, find the record exceptions, file exceptions, and principles related to editing and replaced WorldCat records. Includes how to report errors you can't fix yourself and how to apply for PCC membership.

As part of the Expert Community, you can edit most fields in most WorldCat records.

Record exceptions

You cannot edit the following WorldCat records:

  • PCC records—both BIBCO and CONSER records—are EXCLUDED. These records are identified by one or more of the following field 042 authentication codes: isds/c, lc, lcd, msc, nlc, nsdp, nst, pcc.
    HOWEVER, non-PCC libraries can add or edit specific fields as listed in Database Enrichment. )
  • Records with Encoding Level "E" are EXCLUDED.

Field exceptions

You cannot edit the following fields in WorldCat records:

  • System-supplied data (040 subfield ‡c, Entered)
  • Fields 019, 029, 066, 850, and 938
  • Field 042


First, do no harm

  • NEVER remove correct and accurate information from a WorldCat record (such as classification numbers or subject headings) simply because your institution does not find it useful
  • NEVER change the basic nature of a WorldCat bibliographic record into something different
  • AVOID including local data or local practices in a WorldCat bibliographic record
  • Be cautious about changing bibliographic records with a different Language of Cataloging (identified in field 040 subfield ‡b)

If in doubt, DON"T

  • Do not replace a record solely to change an element that is a matter of cataloger's judgment
  • Consider data within the context of the whole record, rather than in isolation

For complete Expert Community Guidelines, see Expert Community: guidelines for experts.

You can also edit and replace WorldCat bibliographic records in these situations:

  • Upgrade minimal-level records
    Existing encoding level Upgrade to encoding level
    M (less-than-full added from batch) blank
    2 (less-than-full, material not examined) 7 or blank
    3 (abbreviated level) 7 or blank
    4 (Core level) (without field 042) 7 or blank
    5 (Partial (preliminary) level 7 or blank (except CONSER-authenticated serials)
    7 (Minimal level) blank (except CONSER-authenticated serials
  • Database enrichment. You can enrich WorldCat records by adding or editing specific fields in any Full-level record, except an authenticated serial. The fields are listed at

For complete details, see Bibliographic Formats and Standards, chapter 5, Quality Assurance.

Reporting errors you can’t fix yourself (including reporting duplicate records)

Replacing PCC records

The Program for Cooperative Cataloging (PCC) is an international cooperative effort aimed at expanding access to library collections by providing useful, timely, and cost-effective cataloging that meets mutually-accepted standards of libraries around the world. PCC is administered by the Library of Congress; it is not an OCLC program, though OCLC does participate in the governance of PCC.

More information about PCC is on the Library of Congress website.

Libraries that want to replace PCC records in OCLC WorldCat must apply for PCC membership. The first step in applying for PCC membership is attending training for and achieving membership in the Name Authorities Cooperative (NACO). More information about NACO is available at and

There is no cost to join NACO, but training is required. The training itself is free, but libraries wishing to join NACO are responsible for the travel costs of the trainer, or for travel costs to send their staff to the trainer’s location. Online training is also a possibility.

Smaller libraries sometimes find it efficient to join together in a NACO funnel project.