MQOD_* (Object descriptor structure)

See:

MQOD_STRUC_ID "ODbb"
MQOD_STRUC_ID_ARRAY 'O','D','b','b'
MQOD_VERSION_1 1 X'00000001'
MQOD_VERSION_2 2 X'00000002'
MQOD_VERSION_3 3 X'00000003'
MQOD_CURRENT_VERSION 3 X'00000003'
MQOD_CURRENT_LENGTH (variable)