Documenting Identifiers
Unique identifiers in metadata records are becoming more and more important for data citation and attribution and for identifying resources related to the resource being described in the metadata. Some mechanism must exist for ensuring that these identifiers are unique. This can be accomplished by using an identifier scheme that guarantees uniqueness (UUID) or 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.
Metadata Record Identifiers
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 record in the metadata itself.
Resource Identifiers
Metadata must include an unambiguous identifier for the resource that it describes.
Related Resource Identifiers
Metadata records increasingly refer to resources that are related to the resource being described. These external resources can be many different type of things.
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.
