(Originally from KP August, 2012—Vol. 54, No. 3) For an in-country Korean military mail cover to be fully complete, it should essentially have three chops or strikes that say four things:1) it is military mail, 2) it has the military unit number, 3) it has gone thru security, and 4) there should be a round military post office strike with the military post office number. If there is any kind of date, it will be in the middle section of the round military post office strike. No date or only the year might be shown. The usual is to show only the year and the month. For security reasons mail should not give away any secrets, and for that reason the day of the month was usually not given, or it was replaced with a blank plug in the strike. The military would turn its mail over to the civilian postal system, which would then do the delivery. On occasion the civilian post office might cancel/strike the military envelope also, which would add another strike.
From these basics, all of the variations develop; the format for these strikes can vary greatly from unit to unit. The assumption is that each military unit was not given its various chops which would then result in uniformity, but, rather, that each unit had its own chops made locally, thus producing wide variety.

Figure #1 shows the three strikes usually needed for completion. The biggest rectangular box with the 4 Hangul groups says “military mail” (군사우편, guen sa oo pyun). The round strike is the military post office with its number. The three-sectioned rectangular box is a combination strike that gives the military unit number and verifies that it has now gone through security. The “military mail” strike can come in all sizes, can be free of a box, and at times may be the only strike on an envelope. In the older military mail, the strike was in the vertical, while the more recent strikes are all in the horizontal. The oldest vertical strikes were in Chinese characters rather than in Korean Hangul.

Figure #2 is all in Chinese; even the two characters before the number 99 in the round military post office chop is in Chinese, and there is no date showing in the middle section. The 33mm long rectangle on the left is in three sections: military mail at the top, inspector in the narrow middle section, and a blank space at the bottom for the inspector’s chop.