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.

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

$b Similarity (O;NR)
Any similarity measure, suitable to support the decision whether the two records should be merged or not

This field is usually added during automatic data ingest.

For an instruction on how to use it to merge records that have not been flagged as possible duplicates manually see How to merge records which have not been marked for deduplication

1. 831 #1$acnp00081480

{"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