When you order a data sync collection, you enter a field in your records that contains your local system control number (LSN). Your local system number is required to process a collection. If needed, as part of your collection setup, OCLC can find your LSN as long as it's in a consistent place. Your local system number can appear in multiple fields, all of which can be entered in the System tab of the Bibliographic Record Information accordion. If no LSN is found for a submitted collection, or you entered None in the Local System Number Location(s) field, a Database Specialist will contact you.
For your bibliographic collection, your local system number is used to produce Unresolved Cross Reference and Bibliographic Cross Reference reports that list each OCLC control number across from your LSN. You can use this information to help you index the OCLC numbers in your local system. Indexing the OCLC control number links your library's records to other WorldCat services (e.g. WorldCat Discovery).
If your records lack an LSN, you will have difficulty inserting the matching OCLC control number back into your local database record.
The MARC 21 standard, field 001 (Control number) contains the control number assigned by the organization that creates, uses, or distributes the record. However, sometimes libraries do not use field 001 for their own control number. Here are some examples:
- A library retains whatever data is in the 001 from the source records (for example, LCCNs, OCLC control numbers, or vendor numbers).
- Field 001 may be missing from a library's records because:
- The library has deleted the field.
- The field is not used in the local system.
- The field is excluded from records exported from the local system.