Code signifying whether or not the shipment information transaction set includes instructions for pick-up and movement of the shipment; (This code provides a means for the shipper to transmit billing data along with the movement instructions, transmit billing data ahead of the movement instructions, or follow movement instructions with complete billing data at a later date)

If M301 contains code value "S" or "R", then M302 is the date of release. If M301 contains code value "U", then M302 is the estimated date of release.

Date expressed as CCYYMMDD

Time expressed in 24-hour clock time as follows: HHMM, or HHMMSS, or HHMMSSD, or HHMMSSDD, where H = hours (00-23), M = minutes (00-59), S = integer seconds (00-59) and DD = decimal seconds; decimal seconds are expressed as follows: D = tenths (0-9) and DD = hundredths (00-99)

Code identifying the time. In accordance with International Standards Organization standard 8601, time can be specified by a + or - and an indication in hours in relation to Universal Time Coordinate (UTC) time; since + is a restricted character, + and - are substituted by P and M in the codes that follow

M304 reflects the time zone which the time reflects.