Shown here is a military post card used in 1952. The card is a commemorative card, printed to commemorate “Samil Day”. The following extract about Samiljeol is from a 1943 booklet authored by New Ilhan entitled Korea and the Pacific War which was based on a report he prepared for the Office of Strategic Services (OSS).
New Ilhan, Chairman, United Korean Committee in America Planning and Research Board
On that occasion in 1919, men and women, old and young, students, farmers, preachers and shopkeepers, government employees and Korean policemen, all joined in what is considered the greatest peaceful demonstration staged by a people against an alien rule. Six weeks prior to March 1, 1919, the date on which the demonstration took place, groups of leading citizens, more than 50 per cent Christians, in all parts of the country, were organized to plan the program for the event. Women made the forbidden Korean flags by the thousands in hideouts, while students mimeographed instructions and printed the Declaration of Independence. These were bundled into rice straw sacks and distributed secretly throughout the country through underground channels. All this was accomplished in a country that is more tightly policed than any other country, and where the least suspicion of political activity on the part of a Korean is put down ruthlessly. Country folks with loads of wood were used to take the flags and printed matter to the rural districts. Old women hid the precious circulars around their bodies and took them to their villages. Day after day preparations were made and word passed about, but not an official knew of it, or if any Korean working in the government knew of it he did not reveal it. For when the day and the hour (2 P.M. March 1, 1919) arrived the Japanese police and army were completely surprised.
The “Independence News.” which the Koreans published as an out- come of this demonstration, appeared on the desks of all the chiefs of police in the country every day, and in spite of the most frantic search for the culprits who printed and delivered them, they were not able to discover the source for nearly four months. The means which the Koreans used to penetrate the cordon of police and secret 11service men, let alone the military police and gendarmes, is one of the weapons of the Korean organization.

Some of the hanja (Chinese characters) on the card are as follows:
軍事郵便 = Military Post
To: 서울特別市 中区 舟橋洞 二三九番地 Seoul Special City Central District, Jugyo-dong, No. 239 金鍾秀 Kim Jongsu 貴下 (honorific)
From: 第六一八五部隊人事課 Military Post 109 6185 Unit Personnel Section
閲檢 = Censor
Military Post strike partial date 85. (1952) Written on reverse “rec’d 4285.3.10”
Across the bottom of the front of the card is an inscription reading:
三一節記念/삼일절기념 (Samiljeol ginyeom) Commemorating Samiljeol or 3-1 Festival Day referring to March 1, 1919 when Korean activists demonstrated for independence.

Part of the return address reads “Unit 6185”. Such code numbers are Military Unit Cover Designators (MUCD) and are used for security purposes to hide the true unit designation. I have a list of Japanese MUCD used by the Chosen Gun, DPRK MUCD, and a partial list of PLA/CPVA MUCD. Does anyone have any information on ROK MUCD?