A 'code set' or 'enumeration' is a shared list of codes that is used in place of longer names or explanations. In Ed-Fi, where "such classifications are everywhere in school operations and processes", they are called "descriptors". This article discusses at some length the history of descriptors in Ed-Fi and describes some of the rethinking now in progress. "This third generation of thought goes beyond that to think about the mappings of descriptor values (and possibly other elements in the future) from one context to another as data itself." This allows different descriptor values to be used in different contexts, instead of demanding people choose one and only one value. It's a good discussion, and based on my own experience I would say Ed-Fi is moving in the right direction here.