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This is a preliminary revision of CONSER Editing Guide, Field 010, changed to support use of the new MARC 21 LC control number. It is being provided until the next CEG update is distributed, later in 2001. Further reviews before the final update goes for printing may result in minor editorial changes, but main content and policies will remain as presented here.

010  LIBRARY OF CONGRESS CONTROL NUMBER  (NR)

First and second indicator

#  Undefined

Subfields

a  LC control number (NR)
b  NUCMC control number [Not applicable]
z  Canceled/invalid LC control number (R)

Description/Instructions

The LIBRARY OF CONGRESS CONTROL NUMBER is the unique number assigned to an authenticated CONSER record. It is used to manage the processing of the record at the Library of Congress and is the control number under which the record is distributed by the CDS MARC Distribution Service.

The LC control number (LCCN) is input, displayed, and output by OCLC to LC in field 010 (subfield $a). The LCCN is distributed by LC in both fields 010 and 001. LC control numbers are assigned by all CONSER members to records that are originally input, to existing records that were not previously authenticated, and in some cases to previously authenticated records.

Beginning in 2001, newly assigned LCCNs include a four-digit number representing the year of assignment. LCCNs assigned previously, from 1898 to 2000, had a two-digit year portion. Making room for the four-digit year also required changing other portions of the machine-readable LCCN structure, as defined by the MARC 21 Format for Bibliographic Data. Both formats are valid and are used in CONSER records, as they were originally assigned. Earlier forms of LCCN found in printed sources are also still valid for retrospective input. (For instructions, see Appendix P.)

The form required for field 010 input and used for field 010 display of the LCCN (in either format) on the OCLC system is not identical to the MARC-defined LCCN structure or to the form input for LCCN in record control number subfields of linking entry fields. (For details of the LC control number's structures and their history, see Appendix P. For instructions on inputting LCCNs in linking entry fields, see Linking Entry Fields--General Information.)

Beginning in 2000, regular LC control numbers (i.e., unprefixed numbers) are assigned by the Library of Congress and CONSER members to newly input records or first-time authenticated records. Prior to May 1999, regular LCCNs were also assigned by LC catalogers to previously authenticated CONSER records that had "pseudo" control numbers. The unprefixed LCCN in field 010 in OCLC consists of a year portion (four-digit or two-digit, as assigned), then a hyphen, and then a consecutively assigned number of one to six digits in length. (If the consecutively assigned number is less than six digits long, there is no need to input leading zeroes before the number. If leading zeroes are input, the OCLC system deletes them from the display.)

     010 ##  85-645325
     010 ##  68-4897
     010 ##  2001-239001
     010 ##  2001-3292

LC control numbers on records for works cataloged prior to Dec. 1, 1968, may be preceded by alphabetic prefixes. These prefixes can be from one to three characters in length, and are carried in the machine record as lowercase alphabetic characters. In field 010 on the OCLC system, the prefix is input directly preceding the year portion of the LCCN, with no spaces between them. For a complete list of prefixes, see Appendix P.

     010 ##  a62-2407
     010 ##  agr17-1177
     010 ##  ca35-621
     010 ##  map68-359

Numbers structured like LC control numbers, and identified by a "pseudo" prefix, are used in CONSER records for which no regular LC control number exists at the time of authentication. The pseudo LC control numbers usually have their own sequential numbering scheme, i.e., the prefix is a significant part of the numbering inasmuch as the numeric portion may also be valid for other prefixed LC control numbers as well as unprefixed LC control numbers. Input pseudo LCCN prefixes in the same way as other prefixes, as described above.

"sc" prefix. Used prior to 2000 for records authenticated by LC for titles not held by LC or not cataloged by LC as represented by the record. If a title is subsequently received by LC, the "sc" number is cancelled in favor of a regular control number.

     010 ##  sc85-106

"sf" prefix. Used prior to 2000 by LC in originally input or first-time authenticated records when a title is held by LC and given less than full cataloging. This included form card cataloging, minimal level cataloging, and other forms of cataloging for which no printed card exists. Prior to May 1999, LC also assigned "sf"-prefixed LCCNs when giving less than full cataloging to previously authenticated CONSER records.

All records containing an "sf"-prefixed control number also have an 050 field. The information in the field varies.

     010 ##  sf76-208
     050 00  TC1 b .S45

     010 ##  sf77-8
     050 00  CLASSED SEPARATELY

     010 ##  sf93-91310
     050 00  WMLC 93/922

     010 ##  sf85-9857
     050 00  Microfilm 85249

"sn" prefix. Used prior to 2000 in records initially authenticated by NSDP and CONSER members. (Prior to 1984, "sn" control numbers were also assigned to LC minimal level cataloging records.) Sn-prefixed numbers are currently assigned only for LC newspaper cataloging and USNP records.

     010 ##  sn82-9563
     010 ##  sn99-1
     010 ##  sn2001-58302

For National Library of Canada records batchloaded to OCLC with a 001, OCLC derives a "dummy" LC control number from the Canadian serial number in the 001 field, unless an LC control number is already present in field 010.

For NLC records input online, NLC inputs a pseudo control number unless an LC control number is present. The pseudo control number carries, respectively, a "ce" or "cf" prefix for the English and French catalog records, for a bilingual publication. For the single record for a unilingual publication, the prefix "cn" is used. The "cn", "ce", and "cf" numbers for online records are taken from one sequence of numbers.

NOTE: If a regular LC control number exists for an English bilingual record, NLC will input the LC control number in subfield $a of field 010 and will input a pseudo control number, preceded by the prefix "ce", in 010, subfield $z. In the French bilingual record, NLC will input the same pseudo control number, but preceded by the prefix "cf", in subfield $a of field 010. These procedures enable NLC to match the English and French bilingual publications.

"ce" prefix. Canadian bilingual publication, English language cataloging
"cf" prefix. Canadian bilingual publication, French language cataloging
                    (The same number is used for English and French bilingual
                    publications; the prefixes differentiate the two records.)

     010 ##  ce76-73468
     010 ##  cf76-73468
     010 ##  ce2001-790000

"cn" prefix. Unilingual Canadian publication, English or French language cataloging

     010 ##  cn76-83077
     010 ##  cn2001-390000

Prior to January 1999, suffixes, alphabetic identifiers, and revision dates were input at the ends of some LC control numbers. These elements did not affect the uniqueness of the LCCN. They may be encountered during retrospective conversion following LCCNs in printed sources. For examples and information on their former usage, see Appendix P.

The inclusion of these elements was discontinued in 1999. They have been stripped from records in the LC database; and OCLC will remove them from its records in 2000-2001. Do not input suffixes, alphabetic identifiers, or revision dates in field 010.

$a  LC control number. The subfield $a contains the valid control number in one of the forms described above. This portion of the 010 field doubles as the CONSER database's control number and is also converted to field 001 prior to a record's distribution within the CONSER database.

The critical role of the $a as control number dictates that it be accurately input. To avoid possible duplication, the number should be searched on the OCLC system before the record is updated. It is also advisable to add the number to the record as the last step before updating the record. Once a record has been updated through the authentication process, institutions other than LC should not change the $a portion of field 010. If a correction is necessary, the institution must contact LC. (See also C2.2.2.)

The subfield $a in an authenticated record must be a valid control number, i.e., one assigned or verified by the authenticating agency. Control numbers input from other sources by an OCLC institution can only be verified at the time of full LC authentication (042 code "lc"). Thus, if a control number exists in a record prior to its initial authentication by an agency using 042 codes "nsdp", "lcd", or "msc", it must be removed from the $a portion of the 010 before authentication. In this case the unverified number is retained in subfield $z and a new control number is added to the subfield $a. If the record is later given full LC authentication, the number in subfield $z will be verified as correct or incorrect. If correct, it will be restored to the subfield $a; the pseudo-number will be placed in subfield $z. If incorrect, it will be deleted from the record.

$z  Canceled/invalid/unverified LC control number

Subfield $z is used for:

1. Canceled LCCNs: Prior to 2000, if an authenticated CONSER record contained a pseudo LC control number and LC later acquired and cataloged the title, LC added a new control number to subfield $a and moved the CONSER pseudo control number to subfield $z. LC control numbers are also recorded in $z when records are collapsed or duplicate records are canceled.

   Canceled LCCNs from monographic records can also be included in field 010 subfield $z, recorded after canceled LCCN(s) from serial records. It is preferable for canceled LCCNs to be input in numeric order, particularly when recording several canceled numbers on a single record.

2. Invalid LCCNs: If any CONSER or OCLC participant has input an erroneous number in subfield $a, the erroneous number is canceled by LC or NLC and moved to subfield $z. The correct number is input in subfield $a.
3. Unverified LCCNs [CONSER practice]: If an unverified control number exists in the record at the time the record is newly authenticated, the cataloger should move the suspect control number to $z and add a valid number to subfield $a.

   NOTE: When moving an LC control number to 010 subfield $z, input it there in the format used when it was assigned. Therefore, the same record may have an LCCN with four-digit year in subfield $a and one (or more) with two-digit year in subfield(s) $z. Prefixes should be retained. Any suffixes, alphabetic identifiers, and revision data, however, should be dropped.

Subfield z is not used for:

1. The LCCN on LC's printed card cataloging when the type of cataloging differs from the online record (e.g., the online record is a successive entry record; LC's printed card reflects latest entry cataloging).
2. Control numbers input in field 010 of an unauthenticated record by a CONSER member or OCLC institution that prove to be in error when LC authenticates the record.

Related fields, etc. C1, C2, 001, 016, Appendix P.

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