MARC21 Bibliographic records - 010 tag

The LCCN or Library of Congress Control Number, (previously called the LC card number) is found in the 010 tag of MARC21 bibliographic records, is a unique number assigned by the Library of Congress to each catalog record. The number identifies the bibliographic record, not the item itself.

For records created prior to January 2001, the LCCN contained 8 digits, two initial digits representing the year, a hyphen, and the remaining 6 digits representing the record number. Beginning January 2001, the LCCN was created with four initial digits representing the year, a hyphen and the remaining 6 digits representing the record number for a total of 10 digits. Each LCCN should be unique to a record, but errors do occur and all though infrequently, one number can be assigned to more than one item.
The 010 tag has no indicators. The LCCN is found in an "implied subfield" ‡a. On occasion, you may find the LCCN preceded with a ‡z. This indicates that the LCCN listed in that subfield is not valid. On older records the LCCN may be found with prefixes such as agr, e or sa (indicating a specific series of records found at the LC); also prefixes such as cn, ce or cf indicate they are Canadian numbers.

When using the LCCN to search for records in NHU-PAC if the hyphen is present (example 74-00513), it is your choice whether to enter the leading 0's (74-513). If you do not enter them, NHU-PAC supplies them. But if you do not enter the hyphen, you must enter the leading 0's (74000513).

When an LCCN is printed in a book it is typically found on the title page verso. Searching by LCCN is an easy way to find records in NHU-PAC, but keep in mind that not all records have an LCCN. If you don't find a match when searching by LCCN you should try another search (ISBN, title and/or author) before assuming no record is available in NHU-PAC.