|Required if applicable/Required if applicable|
|1st Indicator Undefined|
|2nd Indicator Undefined|
|Subfields (R=Repeatable NR=Nonrepeatable)||Input Standards|
|‡a||LC control number (NR)||Required if applicable/Required if applicable|
|‡b||NUCMC control number (R)||Required if applicable/Required if applicable|
|‡z||Canceled/invalid LC control number (R)||Required if applicable/Required if applicable|
|The LC control number and/or canceled or invalid LC control numbers. (The LC control number was previously called the LC card number.) Prior to January 2001, LC control numbers had two initial digits, a hyphen, and remaining digits. From January 2001, LC control numbers were created with four initial digits, a hyphen and the remaining digits.|
Use the following guidelines to identify LC control numbers:
|Undefined. The 1st indicator position is undefined and contains a blank ( ).|
|Undefined. The 2nd indicator position is undefined and contains a blank ( ).|
A canceled or invalid LC control number must be entered in subfield ‡z, not subfield ‡a. If in doubt, use subfield ‡z.
|‡a LC control number||Assume that the control number on LC cataloging copy or in a publication is valid, unless one of the circumstances described in subfield ‡z applies.|
Entering older LCCNs
Library of Congress Control Numbers have changed since they were first issued in 1898. Use the following guidelines to enter pre-2001 LCCNs:
One digit preceding the hyphen. Enter 0 before such numbers. If you do not enter an initial 0, the system supplies the 0.
Leading zeros following the hyphen. When the hyphen is present, it is your choice whether to enter leading 0's. If do not enter them, the system supplies them. If you do not enter the hyphen, you must enter the leading 0's.
Prefixes. Enter prefixes as lowercase letters immediately preceding the number.
Prefixes of four or more letters. The system does not accept such prefixes. However, it does accept up to three letters as a prefix. If the prefix is four or more letters, substitute equivalents as shown.
Entering pre-1902 LCCNs
Before 1902, LC used various styles for card numbers. For information about pre-1902 card numbers that are not described here, contact OCLC, your OCLC regional service provider or the Library of Congress (Cataloging Distribution Service or the Cataloging Policy and Support Office).
Cards issued in 1898. Some numbers issued in 1898 lack the year or have the prefix C and no year. Enter such card numbers with the prefix c98-.
Cards issued in 1901. Some numbers issued in 1901 have no year but have alphabetic prefixes other than C (e.g., F-3144). Others may be preceded by 1 (e.g., 1-Z-245). Enter the alphabetic prefix in lowercase letters. Enter a 1 or 01 after the prefix (The system provides a leading 0 before 1). Enter the hyphen and the rest of the number.
Suffixes printed after or below the LC card number. Do not input suffixes.
Alphabetic or phrase identifiers. Do not enter the alphabetic identifier CD or phrases such as Additions, Exception, Provisional, Cancel and Brief Cataloging.
Numbers followed by single daggers or asterisks. Enter only the card number.
Double daggers following numbers. Enter only the number.
Slashes and following characters. The number may be followed by a slash and a single digit, by a second hyphen and a single digit, or by a second hyphen, an M and a single digit. Do not enter the slashes, second hyphens, or any of the characters following slashes or second hyphens.
Unrev'd following the number. Do not enter.
Revised or rev following the number to the right of the printing symbol. Do not enter.
Revision dates. The printing symbol (located to the right of the rod hole on LC cards) may include the revision date. Do not enter.
Rev followed by numbers greater than 1. Do not enter.
|‡b NUCMC control number||A valid number for the item as found in the National Union Catalog of Manuscript Collections (NUCMC). The form is prefix ms, two digits, hyphen, remaining digits: ms70-491 or ms68-2403. The NUCMC control number is entered and displays identically to LCCNs in subfield ‡a . |
Any canceled or invalid NUCMC control numbers are in subfield ‡z . Pre-1988 records may have NUCMUC control numbers in subfield ‡a .
|‡z Canceled/invalid LC control number||Invalid control numbers. Use also if the accuracy of the control number is in doubt. If one of the following conditions exists, the LC control number is invalid: |
OCLC also uses subfield ‡z for the control number of the deleted national library record when it merges a national library record and a member-input record.
The British Library uses subfield ‡z to record the LC control number if the LC control number is readily available.
|Field 010 subfield ‡a prints in the lower right corner (bottom line).|
If a particular catalog entry requires two or more physical cards (continuation cards), the LC control number prints on the final card.