The ISO Data Category Registry ISO 12620:2009 introduces – A web-based electronic Data Category Registry (DCR) for simple, complex and (in the future) container Data Categories (DCs) – ISO DIS compliant Persistent IDentifiers (PIDs) for each DC, e.g., – The DC Reference schema, a small XML vocabulary, to embed these DC PIDs in XML documents, e.g.,

Standards and Data Category references Some standards already provide their own constructs for embedded DC references However, these constructs sometimes – Use ambiguous DC identifiers instead of PIDs – Are not able to handle the current DC PIDs – Do not cover all DC types, i.e., container, complex and simple DCs

SpecificationCan handle DC PIDs?Handles DC typesSuggestion DTDsNoNoneUse Relax NG or XML Schema instead Relax NGYesAllUse the DC Reference vocabulary XML SchemaYesAllUse the DC Reference vocabulary TEI ODDYesAllUse TMFYesComplex DCsUse Relax NG of XML Schema instead, and use the DC Reference vocabulary LMFUnspecified Use the DC Reference vocabulary for an LMF compliant schema TBX XCSYesComplex DCsValue picklist needs to be opened up and may need provisions for the upcoming container DCs GeneterNoNoneUse Relax NG or XML Schema instead or use the DC Reference vocabulary in the instance MAFYesComplex and simple DCsMay need provisions for the upcoming container DCs LAFYesComplex DCsNeeds provisions for the other DC types

Improving the current situation Use Relax NG, XML Schema or ODD instead of DTD Create open schemas, which allow adding attributes and/or elements from foreign namespaces, or embed dcr:datcat or dcr:valueDatcat hooks at the proper places in the schemas The DC Reference vocabulary can then be used to embed DC references for various DC types at the right places For existing specifications with some support for DC references, make sure all relevant DC types can be covered, and make use of DC PIDs

References Latest version of the DC References vocabulary – Survey of the support for DC references – M.A. Windhouwer, S.E. Wright, M. Kemps- Snijders. Referencing ISOcat data categories. In proceedings of the LRT standards workshop (LREC 2010), Malta, May 18, 2010.Referencing ISOcat data categoriesLRT standards workshopLREC 2010 –

ODD example … unknown the text is freely available. … Note: this example does use PIDs from the ISOcat test server.

LMF example … <feat att="partOfSpeech" dcr:datcat=" val="commonNoun" dcr:valueDatcat=" <feat att="writtenForm" dcr:datcat=" val="clergyman"/> … Note: once the DCR supports container data categories LexicalResource, LexicalEntry and Lemma could also have dcr:datcat attributes.

LAF example … Note: each value needs it’s own DC reference hence the addition of the valueDescription element.