Documenting Identifiers
The importance of unique identifiers for data is well understood in terms of data citation and unambiguous attribution. As metadata are shared between National and International repositories it is becoming increasing important to be able to unambiguously identify and refer to specific records. This requirement is facilitated by including an identifier for metadata and data in the metadata. Some mechanism must exist for ensuring that these identifiers are unique. This is accomplished by specifying the naming authority or namespace for the identifier. It is the responsibility of the manager of the namespace to ensure that the identifiers in that namespace are unique.
Crosswalks
Concept | Description | Paths |
---|---|---|
Metadata Identifier | A unique reference to the record within the catalogue (Metadata Identifier) | DIF /dif:Entry_Id ISO /*/gmd:fileIdentifier/gco:CharacterString |
Resource Identifier | Identifier for the cited resource | DIF /dif:DIF/dif:Data_Set_Citation/dif:Dataset_DOI DIF /dif:DIF/dif:Reference/dif:DOI ECHO /echo:Collection/echo:DataSetId ISO /*/gmd:identificationInfo/*/gmd:citation/gmd:CI_Citation/gmd:identifier/gmd:MD_Identifier/gmd:code/gco:CharacterString ISO-1 //cit:CI_Citation/cit:identifier/cit:MD_Identifier/cit:code THREDDS /thredds:catalog/thredds:dataset/@thredds:ID netCDF /nc:netcdf/nc:attribute[@name=id]/@value |
Naming Authority | The organization responsible for the maintenance of the identifier (namespace) | ISO /*/gmd:identificationInfo/*/gmd:citation/gmd:CI_Citation/gmd:identifier/gmd:MD_Identifier/gmd:authority ISO /*/gmd:identificationInfo/*/gmd:citation/gmd:CI_Citation/gmd:identifier/gmd:MD_Identifier/gmd:codeSpace (19115-1) THREDDS /thredds:catalog/thredds:dataset/@thredds:authority netCDF /nc:netcdf/nc:attribute[@name=naming_authority]/@value |
Parent Identifier | A unique identifier for a parent dataset or collection | DIF /dif:DIF/dif:Parent_DIF ISO /*/gmd:parentIdentifier/gco:CharacterString |
xPath Note: The xPaths included in this table use several wildcards. // means any path, so //gmd:CI_ResponsibleParty indicates a gmd:CI_ResponsibleParty anywhere in an XML file. /*/ indicates a single level with several possible elements. This usually indicates one of several concrete realizations of an abstract object. For example /*/gmd:identificationInfo could be gmd:MD_Metadata/gmd:identificationInfo or gmi:MI_Metadata/gmd:identificationInfo and gmd:identificationInfo//*/gmd:descriptiveKeywords could be gmd:identificationInfo/gmd:MD_DataIdentification/gmd:descriptiveKeywords or gmd:identificationInfo/srv:SV_ServiceIdentification/gmd:descriptiveKeywords.