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956 Remote access to external systems (O;R)

Field Definition and Scope

This field holds the essential data that are necessary to trigger a retrieval operation in an external database system. The aim is to provide further information related to the described entity, which is out of scope of the CERL Thesaurus such as sample bibliographic records or provenance information. The technique used to access the remote system is a JavaScript-based creation of a HTTP-Get request or an automated submitting of an HTML form (HTTP-Post). Each system code given in $n corresponds to a particular request algorithm within the CT web interface. Therefore codes other than on the List of System Query Codes must not be used without prior consultation with the Data Conversion Group.

Application of Content Designators


Indicator 1: undefined (blank) Specifies the subfield used to create a query * 4 use the record identifier given in $u as search term * 7 use the content of $y as search term * 8 use one or all of the headings given in 2XX as search term

Indicator 2: Specifies the type of information retrieved in the external system:

  • 0 sample bibliographic record
  • 1 provenance information
  • 2 information about the described entity
  • 3 depiction
  • 8 other record for the same entity (owl:sameAs) 1)
  • 9 other 2)


$0 Source of information (NR)
This subfield is added in an automated updating process only. The content of this subfield is still experimental.
Do not edit this subfield manually!\\

$0 Type of Resource (M;NR)
A four character code indicating the type of the external dataset this field links to. Currently, the following values are supported:

Code Meaning 2nd Indicator position
biblbibliographic record0
provprovenance information1
infogeneral information2
samedescribes the same entity8

$6 Source file reference (NR)
This subfield is added in an automated updating process only and shall be removed after manual amendment of the record.
Do not edit this subfield manually!

$c Rights statement (O;NR)
A statement on the copyrights, licenses etc. Particularly in regard to portraits etc. It consists of the name of the right holder, the License / Copyright status and and URL (to the page where the item and its license is described (e.g. Wikimedia Commons), each separated by two dashes, preceded and followed by a blank (). If the rights holder requests any specific text to idicate the license, use this instead of their name. If this prescribed text refers to either or both the license by its official name or acronym and the URL of a resource describing item and license, one or both of the other parts of this statement can be omitted (see below for an example)

$n System Code (M;NR)
A four character alphanumeric code assigned by DCG.

$u Record identifier (NR)
The record identifier that should be used as a search term in the remote system

$y Alternative Search term (M;NR)
A search term other than the record identifier used to retrieve the wanted records in the remote system

$8 Language Code (O;R)
Must precede any subfield $z. See the description of numerical subfields.

$z Public note (O;R)
Text to be displayed as a link in the CT web front-end.

Input Conventions

If the second indicator holds 8, $y must contain a full URI.


  1. 956  1$nGOES$zProvenance Information$u365984574
  2. 956  3$0dpct$nLINK$yhttps://upload.wikimedia.org/wikipedia/commons/4/47/PhilippMelanchthon.jpg
           $cPublic Domain -- https://commons.wikimedia.org/wiki/File:PhilippMelanchthon.jpg$8eng
           $zLucas Cranach the Elder, Portrait of Philipp Melanchthon, 1543
  3. 956  3$0dpct$nLINK$yhttps://upload.wikimedia.org/wikipedia/commons/f/f6/Hannover_Skyline.jpg$8ger
           $zSkyline von Hannover$cThis Wikipedia and Wikimedia Commons image is from the user Chris 73 and is 
           freely available at http://commons.wikimedia.org/wiki/File:Hannover_Skyline.jpg under the creative 
           commons cc-by-sa 3.0 license.

Internal Representation

{"data": {"extDataset": [{
    "typeOfResource": "Type of Resource ($0)",
    "code": "System query code ($n)",
    "searchTerm": "Search Term ($y)",
    "note": [{
        "text": "Public note ($z)",
        "lang": "Language code ($8)"

Change History

  • 17.07.2017: First indicator position becomes obsolete once the CT has been migrated into its new environment
  • 17.07.2017: Subfields $6 and $u will no longer be supported, once the CT has been migrated into its new environment. Any subfield $u will be mapped to $y during ingest.
  • 17.07.2017: Added new subfield $8.
  • 17.07.2017: Removed experimental subfield $0 from format description
  • 17.07.2017: Added new subfield $0 to format description.
  • 09.08.2017: Added new subfield $c
Use only if the server returns RDF from this URI
Once the CT has been migrated into its new environment, this indicator position becomes obsolete and is kept only for backwards compatibility. Any information in subfield $0 will take precedence over the information coded here
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 resources/cerl_thesaurus/editing/format/956.1502268537.txt.gz · Last modified: 2017/08/09 10:48 by jahnke



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