Military acronym for "Rear Entry Mother Fucker". Used to describe any who sits behind a desk an only propose in life is to ruin peoples lives because they do not know any better or lack of common sence. Most popular examples are Quartermasters, Intelligences Officers, any Officer in an executive or non-combat position and those who work in the Pentagon on up.
It also describes the way their office is set up. Where you have to walk around the desk to enter from the rear. The desk also faces the door so in case there is a scuffle you have to go over their desk to get your hands around their throat.
"That damn Intel Officer is a REMF he sent us to the wrong coordinates"
"The Quartermaster would not issue us night vision goggles for the tonight's mission, what a REMF"