The EIDR Registry makes a very clear distinction between Abstraction and Edit IDs. A particular work will only ever have one Abstraction ID, but it may have any number of Edit IDs, each for a different derived version of the abstract work. Some master title management systems contain only records of a particular type: i.e., IMDb contains only Abstraction and Series records. Others contain mixed, but clearly identified types: i.e., the EIDR Registry. Opportunities for mischief arise when a single system contains a mixture of loosely defined record types or when it is not immediately obvious what kind of records are actually at hand. When considering how to map the records in a particular data set to the EIDR registry, begin with this question:
Is it ever possible for one abstract work to have more than one record or a different internal ID, now or at any point in the future?
If the answer is, “Yes,” then the data set contains at least some product/version level records that will likely map to EIDR Edit records.
Before obtaining EIDR IDs for a data set, take particular care to identify the type of records contained within. In many cases, what first appears to be a set of Abstraction records is in reality a set of Edit, product, or version records. If this is the case, then a preliminary step to identify the appropriate EIDR Abstraction IDs that must be introduced before the necessary EIDR Edit IDs can be matched or registered.