Specifies a new collating sequence for the named domain. The OpenVMS National Character Set (NCS) utility provides a set of predefined collating sequences and also lets you define collating sequences of your own. The COLLATING SEQUENCE clause accepts both predefined and user-defined NCS collating sequences. Before you use the COLLATING SEQUENCE clause in an ALTER DOMAIN statement, you must first specify the NCS collating sequence for SQL using the CREATE COLLATING SEQUENCE statement. The sequence name argument in the COLLATING SEQUENCE clause must be the same as the sequence name in the CREATE COLLATING SEQUENCE statement.