It would be helpful to clarify that, in the context of a dcat:Resource, the value of a dcterms:identifier denotes the resource being catalogued.
This is different to the identifier for the metadata record or catalog entry, which of course is the URI of the dcat:Dataset or dcat:DataService node, etc.

This in response to a discussion in a meeting of the Australian government geospatial metadata working group which I am currently sitting in.

Currently the definition of dct:identifier just copies the DCMI definition 'A unique identifier of the item.'