In the old Nabble archive post, DRH states that NULLS always sort first, which is not specified in the SQL92 standard, but is left up to implementations. I'm not asking how to collate NULL values, I'm asking if there is an explicit guarantee in the API that SQLite will always take care of sorting the NULLS first, and that a collation sequence will not have make sure to do so. That certainly appears to be the case.