Data Link Management - D. This message uses an optional tag that should not be reused. The spare at the end is used to byte align the message. S 1 AS FATDMA RATDMA ITDMA BASE AIS message number. Must be 20 20 Indicated how many times a message has been repeated 0 default do not repeat any more 1 Unique ship identification number (MMSI) 1193046 Not used. Should be set to zero. 0 Reserved offset number 0 10 Number of reserved consecutive slots 0 1 Time-out value in minutes min 0 1 Increment to repeast reservation of this block 0 14 Reserved offset number (optional) 0 20 Number of reserved consecutive slots (optional) 0 NoReturn 2 Time-out value in minutes (optional) min 0 NoReturn 2 Increment to repeast reservation of this block (optional) 0 NoReturn 24 Reserved offset number (optional) 0 30 Number of reserved consecutive slots (optional) 0 NoReturn 3 Time-out value in minutes (optional) min 0 NoReturn 3 Increment to repeast reservation of this block (optional) 0 NoReturn 34 Reserved offset number (optional) 0 40 Number of reserved consecutive slots (optional) 0 NoReturn 4 Time-out value in minutes (optional) min 0 NoReturn 4 Increment to repeast reservation of this block (optional) 0 NoReturn 44 This field is a serious pain. This padding makes the message byte aligned 0