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Program for Cooperative Cataloging

The Library of Congress > Cataloging, Acquisitions > PCC > CONSER > About CONSER > Short Guide to CONSER Authentication

(and a couple of other fields people have had questions about)

Fixed field codes:

Encoding Level See CEG, Section E, Encoding Level (Leader/17) for instructions on changing existing OCLC codes, I, K, L, M, to MARC 21 codes used in CONSER records. In general, you may replace code "I" or code "K" with code "blank", but do not replace a higher level code with a lower level code.

Codes "blank" or 7 would most often be used by CONSER members. LC also uses 5, the US ISSN Center uses 8, see the CEG for definitions of these codes and how to treat them if you find them.

Source code: CONSER members use codes "c" (cooperative cataloging program) or "blank" (national bibliographic agency, i.e. DLC, NLC, NLM, and AGL) according to the definitions in the CEG. Source code "d" (other) must be changed to "c" or "blank" as appropriate when authenticating a previously unauthenticated record.

Variable fields:

010 $a Library of Congress Control Number (LCCN).

All authenticated CONSER records contain a valid LCCN in subfield $a of the 010. CONSER members add a valid LCCN to each record they originally input or each existing unauthenticated OCLC record that is being authenticated. Each CONSER member is assigned a unique, sequential block of LCCN for authenticating records. It is important that the number be input correctly so that it does not duplicate an LCCN already on a record in the database. Once a record has been updated through the authentication process, institutions other than LC should not change the $a portion of field 010. Please be sure that once an LCCN is added to one record, it is not accidentally used on another record- some people remove the sticky label for each used LCCN or strike through the LCCN they have used to guard against this.

The presence of 010 $a and a valid 042 code cause the record to flow to the CONSER database. 010 and 042 are the primary identifying fields of an authenticated record. (See CEG C2, 010, 042).

012 CONSER Fixed Length Field

CONSER members do not add this field to any record they create or authenticate. This field is not associated with authentication, but described here because there has been some confusion around its appearance on authenticated records and past use.

012 may appear on some existing CONSER authenticated records, basically the only subfields you might need to be concerned about are $b and $z- and you won't often need to deal with them in authenticated records you are making changes to.

$b is found on some LC authenticated records, a lot of the time it's already set with the correct value 3 (see CEG 012, $b, p. 2). CONSER participants are responsible only for the following when they've made changes to a record containing the value: subfield $b with codes "0" or "7" must be changed to "3" or the entire subfield $b deleted (deleting the subfield will automatically reset the it to the correct value.) The impact of not catching this is minimal, the record will still get distributed. We are asking members to continue to change it if possible for consistency in LC's local processing of records.

$z is used to delete an authenticated CONSER record from the CONSER database as it is processed by CDS and distributed to subscribers. CEG C7.5 has instructions for doing this, but this would probably be a rare occurrence. Questions about record deletion can be directed to the CONSER Coordinator,

042 Authentication Code

CONSER members use codes "pcc" or "msc" depending on the level of authentication of the record. See the definitions of these codes in the CEG 042. Codes "lc" and "lcd" were superseded by "pcc" May 1, 2009 but may remain in some valid existing records. Do not add additional codes to a record containing "pcc", "lc", "lcd", or "nlc", although CONSER catalogers may modify records with these codes. See CEG C2 for detailed information on the authentication process.

050 Library of Congress Call Number

CONSER members will use 050 14 when adding 050. See complete definitions for the indicators in the CEG.

7XX Linking fields

See general information in the CEG on linking entry fields. The OCLC and the LCCN are recorded in subfield $w as record control numbers, the ISSN of the related resource is recorded in $x when available.

850 Holding Institution

According to the CEG, this field is optional. LC serials catalogers continue to use it in many cases because of a local need. If other institutions find it useful, it could be used (but generally don't worry about it, it is not a field associated with authentication.)


See instructions in the CEG, 936 for CONSER use and pre-AACR2 use.

Other topics in the CEG

Please read sections B and C of the CEG for a complete overview of CONSER authentication practices and record modification guidelines. For the fixed and variable fields, you should look at the section that describes the particular field for definitions, coding practice, and interpreting unusual codes you find on a record. Here are some selected topics in the CEG:

CONSER philosophy of record modification: when to leave as is, when to change (cf. CEG B1.7-B1.9, B2.1, B3, B4)

Current cataloging, new input of original records, first time authentication of existing unauthenticated records, modification of an existing authenticated record (cf. CEG B3.1-B3.3)


  • US ISSN Center pre-pubs (cf. CEG C6.1)
  • Reporting duplicates (cf. CEG C7)
  • Record consolidation Procedures (cf. CEG C8)
  • Statistics: Reporting stats (cf. CEG C13)

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