MARC 21 Concise Authority: Control Subfields

This is an ARCHIVED VERSION of the 2000 electronic edition of the MARC 21 Concise Formats. Please see www.loc.gov/marc/concise/ for the most up-to-date version of the electronic MARC 21 Concise Formats.

This section contains descriptions of four subfields that are used to link field data to specific institutions, to other records, or to other fields. These subfields are defined for several ($0 (Record control number) and $5 (Institution to which field applies)) or most $6 (Linkage), and $8 (Field link and sequence number)) fields in the format, thus their descriptions are brought together in this section. The subfields are included in field level subfield lists wherever they are defined, with pointers to this section.

• $0 - RECORD CONTROL NUMBER
• $5 - INSTITUTION TO WHICH FIELD APPLIES
• $6 - LINKAGE
• $8 - FIELD LINK AND SEQUENCE NUMBER

$0 - RECORD CONTROL NUMBER

Subfield $0 contains the system control number of the related authority record preceded by the MARC code, enclosed in parentheses, for the system to which the control number applies. The sources of the MARC code are MARC Code List for Organizations (maintained by the Library of Congress) and Symbols and Interlibrary Loan Policies in Canada (maintained by the National Library of Canada).

710	20$aRoyal Society of Medicine Services (Great Britain) $0(DLC)n##86108151#
511	21$aCongrès européen de droit rural $0(DLC)n##82111965#
730	#0$aDead Sea scrolls $0(DLC)n##79071139
751	#0$aZimbabwe $0(DLC)n##80089993

$5 - INSTITUTION TO WHICH FIELD APPLIES

Subfield $5 contains the MARC code of the institution or organization that has added a tracing, reference, or linking entry field to an authority file record. It is used for institution-specific information that may or may not apply to the universal use of the authority record.

The sources for the MARC code are the MARC Code List for Organizations (maintained by the Library of Congress) and Symbols and Interlibrary Loan Policies in Canada (maintained by the National Library of Canada).

$6 - LINKAGE

Subfield $6 contains data that links fields that are different script representations of each other. Subfield $6 may contain the tag number of an associated field, an occurrence number, a code that identifies the first script encountered in a left-to-right scan of the field, and an indication that the orientation for a display of the field data is right-to-left. A regular (non-880) field may be linked to one or more 880 fields that all contain different script representations of the same data. Subfield $6 is structured as follows:

$6<linking tag>- <occurrence number> / <script identification code> / <field orientation code>

Subfield $6 is always the first subfield in the field.

Descriptions of multiscript record models, with examples, are in the Multiscript records section; specifications for field 880 are in the Other Variable Fields; specifications for character sets and repertoires for scripts are found in MARC 21 Specifications for Record Structure, Character Sets, and Exchange Media.

Linking tag and occurrence number
The Linking tag part contains the tag number of the associated field. This part is followed immediately by a hyphen and the two-digit occurrence number part. A different occurrence number is assigned to each set of associated fields within a single record. The function of an occurrence numberis to permit the matching of the associated fields (not to sequence the fields within the record). An occurrence number may be assigned at random for each set of associated fields. An occurrence number of less than two digits is right justified and the unused position contains a zero.

When there is no associated field to which a field 880 is linked, the occurrence number in subfield $6 is 00. It is used if an agency wants to separate scripts in a record (See the Multiscript Record section. The linking tag part of subfield $6 will contain the tag that the associated regular field would have had if it had existed in the record.

Script identification code
The occurrence number is followed immediately by a slash (/) and the script identification code. This code identifies the alternate script found in the field. The following codes are used:

 

Code	Script
(3	Arabic
(B	Latin
$1	Chinese, Japanese, Korean
(N	Cyrillic
(2	Hebrew

880	1# $6100-01/(N$a<Heading in Cyrillic script>

The entire field need not be in the script identified in subfield $6. If more than one script is present in the field, subfield $6 will contain the identification of the first alternate script encountered in a left-to-right scan of the field.

Note also that the script identification code is used in field 880, subfield $6, but this data element is not generally used for subfield $6 of the associated regular field. In the associated field, the data is assumed to be the primary script(s) for the record.

Orientation code
In a MARC record, the contents of field 880 are always recorded in their logical order, from the first character to the last, regardless of field orientation. For a display of the field, the default field orientation is left-to-right. When the field contains text that has a right-to-left orientation, the script identification code is followed by a slash (/) and the field orientation code. The MARC field orientation code for right-to-left scripts is the letter r. The orientation code is only included in fields with right-to-left orientation, since left-to-right orientation is the default orientation in 880 fields. (See MARC 21 Specifications for Record Structure, Character Sets, and Exchange Media for a detailed description of field orientation.)

880	## $6675-00/(2/r$a<Source citation in Hebrew script>

Note that the orientation code is used in field 880, subfield $6, but this data element is not generally used for subfield $6 of the associated regular field. In the associated field, the data is assumed to be the usual orientation of the primary script(s) for the record.

$8 - FIELD LINK AND SEQUENCE NUMBER

Subfield $8 contains data that identifies linked fields and may also propose a sequence for the linked fields. Subfield $8 may be repeated to link a field to more than one other group of fields. The structure and syntax for the field link and sequence number subfield is:

$8<linking number.sequence number> \ <field link type>

Sequence number
This number is separated from linking number by a period "." and is optional. It is a variable-length whole number that may be used to indicate the relative order for display of the linked fields (lower sequence numbers displaying before higher ones). If it is used it must occur in all $8 subfields containing the same linking number.

Field link type
This code is separated from preceding data by a reverse slash "\". It is a code indicating the reason for the link and it follows the link number, or sequence number if present. No field link types have been defined in the MARC 21 Format for Authority Data.

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