Europeana record id form is /DATASET_ID/LOCAL_ID and it is used in SPARQL-queries, record links etc.
Description for dataset_id (ref)
The identifier of the dataset containing the record. It is typically a 5 digit integer number made of an initial 3 digit number that identifies the provider and following 2 digit number that identifies the actual dataset for that provider.
Description for edm:datasetName
Literal 0..1 This property holds the identifier given to the dataset in Europeana. Example value 00101_M_PT_Gulbenkian_biblioteca_digital
Example link
Example proposal
List of dataset providers
Sample data for the sets (OAI:PMH)
Downloadable dumps