River Assault Group 23 (GD23XP in Vietnamese) was stationed in Vinh Long province in the delta. The cover was sent from patrol boat 1533, according to the letter's contents.
The cover received a nice Hai Quan Viet-Nam (Vietnamese Navy) military mail hand stamp on sending from KBC 3323.
The cover was also hand stamped with a military police insignia, depicting crossed pistols over a star. The recipient was a military policeman from Company D7 on Phu Quoc Island, served by KBC 4286.
The handwritten note at the bottom of the envelope, “thu 0 nguoi nhan xin hoan lai kbc 3323," means “unknown recipient, return to sender”. The MP insignia handstamp was probably applied as part of the return routing.