c. 1968 — Western Pacific
As a Marine enroute to Okinawa/Viet Nam in late 1968, I remember everyone on our plane getting handed a letter. This letter was basically 'Rules to live by' while in Viet Nam, with an emphasis on the fact that we were going to be a 'Guest' there.
A colleague of mine is producing a documentary and would love to get his hands on either an original copy of that letter, or, the exact verbage of the letter.
I can be reached at firstname.lastname@example.org