SourceDescription.sortKey is described in both the Records and RS spec. Is intended to be part of both specs or should it only be part of one?
I think it's okay to leave it in there; it has application to both contexts. It's important for records to preserve record order and it's important to RS for client-side sorting purposes. It doesn't conflict, so I think it's okay to leave it in both.
Thanks for the report, though.