For OneRoster 1.1, in both CSV and REST API bindings the enumerated vocabularies MUST NOT be extended.  If the vocabularies are extended, the CSV file or JSON Payload containing the new value is invalid.  

All of the vocabulary values are string-based tokens that are case-sensitive i.e. the values ‘active’ and ‘Active’ are NOT the same. For OneRoster 1.2, in both CSV and REST API bindings many (but NOT all) of the enumerated vocabularies MAY be extended.  There is a strict naming convention that MUST be used when extending a vocabulary.