Should Identifier be required and unique?

[jeffstazer]

According to the dataset_schema
only these fields are required ("required" : [ "title", "types", "creators" ]). So Identifier is NOT required.

Conversely, the Open Archives Initiative wants a unique identifier.

So, these two elements are not in line with each other. Or we shouldn't be using Identifier for the oai-pmh webservice.

[JohnLevander]

How many of our objects don't have an identifier?

[jeffstazer]

11 identifiers are NULL which are approved and public.

60 identifiers are not unique. All are 'identifier will be created at time of release'.