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Authority control field elements

Find details about the elements of the authority control field.

Each control field contains alphanumeric data. Specific data elements are identified by position within the control field, not by subfield codes and delimiters. Control fields may not be repeated in the authority record. Each control field is followed by a field terminator.  

In OCLC-MARC Records, any element, value, field, subfield, etc., marked obsolete is no longer valid. Current records will not contain these invalid codes. However, previously exported records may contain obsolete MARC coding.

Ind = Indicator  |  SFC = Subfield code  |  R = Repeatable  |  NR = Nonrepeatable  |  Blank = Blank

Tags 001-005

 Note: Mnemonics that appear on workforms and record displays follow the leader label.

Tag Byte Value Definition
001     Control Number (NR)
00-02   oca OCLC designation

Authority record number (ARN)

  • Right-justified with leading zeros
11   Blank

Control Number Identifier (NR)

  • All records contain OCoLC

Date and Time of Latest Transaction (NR)

  • Connexion: On export, the export action itself is treated as the “latest transaction” and so the export date is written to the 005.
00-03   Year
04-05   Month
06-07   Day
08-09   Hour
10-11   Minute
12-13   Second
14   Decimal point

Decimal second

  • Always = 0

Tag 008


Tag Byte Value Definition

Fixed-Length Data Elements—General Information (NR)

  • All 008 fields = 40 data bytes and a field terminator
  00-05   Date Entered on File (Entered)
  06   Direct or Indirect Geographic Subdivision (Geo subd)
    Fill character
    Blank Not subdivided geographically
    i Subdivided geographically—indirect
    n Not applicable
  07   Romanization Scheme (Roman)
    Fill character
    c Converted to Pinyin
    n Not converted to Pinyin
  08   Blank
  09   Kind of Record (Auth/ref)
    a Established heading
    b Untraced reference
    c Traced reference
    d Subdivision
  10   Descriptive Cataloging Rules (Rules)
    a Earlier rules
    b AACR1
    c AACR2
    d AACR2 compatible heading
    n Not applicable
  11   Subject Heading System/Thesaurus (Subj)
    a Library of Congress Subject Headings
    b LC subject headings for children’s literature
    n Not applicable
  12   Type of Series (Series)
    a Monographic series
    b Multipart item
    c Series-like phrase
    n Not applicable
    z Other
  13   Numbered/Unnumbered Series (Ser num)
    a Numbered
    b Unnumbered
    c Numbering varies
    n Not applicable
  14   Heading Use—Main or Added Entry (Name use)
    a Appropriate as main or added entry
    b Not appropriate as main or added entry
  15   Heading Use—Subject Added Entry (Subj use)
    a Appropriate as subject added entry
    b Not appropriate as subject added entry
  16   Heading Use—Series Added Entry (Ser use)
    a Appropriate as series added entry
    b Not appropriate as series added entry
  17   Type of Subject Subdivision (Subdiv tp)
    Fill character


 Note: Value obsolete

    n Not applicable
  18-27   Blanks
  28   Type of Government Agency (Govt agn)
    Fill character
    Blank Not a government agency
    a Autonomous or semi-autonomous component of Malaysia
    c Multilocal
    f Federal/national
    i International/intergovernmental
    l Local
    m Multistate
    o Government agency—type undetermined
    s State, provincial, territorial, dependent, etc
    u Unknown if heading is a government agency
    z Other
  29   Reference Evaluation (Ref status)
    a Tracings are consistent with heading
    b Tracings are not necessarily consistent with heading
    n Not applicable
  30   Blank
  31   Record Update in Process (Upd status)
    a Record can be used
    b Record is being updated
  32   Undifferentiated Personal Name (Name)
    a Differentiated personal name
    b Undifferentiated personal name
    n Not applicable
  33   Level of Establishment (Auth status)
    a Fully established heading
    b Memorandum
    c Provisional
    d Preliminary
    n Not applicable
  34-37   Blanks
  38   Modified Record (Mod rec)
    Blank Not modified
  39   Cataloging Source (Source)
    Blank National bibliographic agency

LC shared cataloging for the National Agricultural Library (DNAL)

 Note: Value obsolete


LC shared cataloging for the National Library of Medicine (DNLM)

 Note: Value obsolete

    c Cooperative cataloging program