831 Duplicate control field (O;R)

This field is used for database updating purposes only. It shall not be displayed in the WWW interface, nor shall its content be edited by a cataloguer.

Indicator 1: none

Indicator 2: Specifies the type of duplicate reference:

• 0 The record indicated in $a was reviewed by a cataloger and merger of the current and the indicated record into one is deprecated.

• 1 The record indicated in $a is probably a duplicate to the present record and should therefore be revised by a cataloguer.

• 2 The record indicated in $a will be merged to the present record in an updating process, since a cataloguer has considered it referring to the same entity.

$8 Language code (O;NR)
Mandatory to precede the $n subfield. A three letter language code from the Marc Code List for Languages.

$a Record Identifier (M;NR)
Record ID of the record considered duplicate

$b Similarity (O;NR)
Number of identical forms or other data detected by a checking routine. The number of matches should be understood as an indication of the similarity of the two records. Any similarity measure, suitable to support the decision whether the two records should be merged or not

$n Cataloguer's note (O;NR)
A short description of the duplicate checking which took place.

$z Original Authority File (A;NR)
Indicates the Authority File from which the record was taken originally.

1. 831 #1$acnp00081480$b1$zNeNKHB$8ger$nDatensatz möglicherweise dublett (Übereinstimmung in Namensform).

{"meta": {
    "distinctFrom": ["Record ID ($a)"],
    "sameAs": ["Record ID ($a)"],
    "possibleMatch": [{
        "id": "Record ID ($a)",
        "similarity": "Similarity ($b)"
    }]
}}

• 17.07.2017: Subfields $8, $n and $z are no longer supported, once the CT has been migrated into its new environment