LC Guidelines:  001  Control Number

NACO:

Structure:  Control numbers used in Name/Series authority records contributed through NACO have the following structure:

Alphabetic prefix - Two (records originally contributed 2001+) or three (records originally contributed prior to 2001) character positions contain the alphabetic prefix.  The prefix is carried as lowercase characters; it is left justified and unused positions contain blanks.  The valid control number prefixes for name and series authority records are (# = blank):

n##

Name and series authority records originally input prior to 2001 using LC's internal system

n#

Name and series authority records originally input 2001+ using LC's internal system

nb#

Name and series authority records originally contributed prior to 2001 via the British Library

nb

Name and series authority records originally contributed 2001+ via the British Library

no#

Name and series authority records originally contributed prior to 2001 via OCLC

no

Name and series authority records originally contributed 2001+ via OCLC

nr#

Name and series authority records originally contributed prior 2001 via RLIN

nr

Name and series authority records originally contributed 2001+ via RLIN

SACO:

Subject authority records are not normally contributed in machine-readable form from sources outside the Library of Congress.


LC:

NAMES/SERIES:

Library of Congress and NACO control numbers have the same structure.  See NACO section above.

Control numbers for Name/Series authority records created using LC's internal system have the following alphabetic prefix:

n##

Name and series authority records originally input prior to 2001

n#

Name and series authority records originally input 2001+

Name/Series authority records created by LC catalogers using OCLC or RLIN have control numbers beginning with the prefixes “no” or “nr” as above.

SUBJECTS:

Control numbers for Subject authority records created using LC’s internal system have the following alphabetic prefixes:

sh#

Subject heading authority record originally input prior to 2001

sh

Subject heading authority record originally input 2001+

sp#

Subject (Proposed) authority record originally input prior to 2001

sp

Subject (Proposed) authority record input 2001+

sj#

Subject (Juvenile) authority record originally input prior to 2001

sj

Subject (Juvenile) authority record input 2001+

For more information on LC Guidelines, select:

Introduction  (LC Guidelines)

To return:

LC Guidelines

MARC 21 Format for Authority Data:  Contents