1) Military slang for when a person is doing their own thing, "singing to their own tune", and generally just acting different or seeming to be in their own world.
2) Also military slang for when an object is not working properly.
2) "My laptop is OFP. It keeps giving me error messages when I try to shut it down."
People that are average, normal, and can be relied on not to "stir the pot."
Zenia: Nah, I've been a bit out of the loop, mainlining PCP and whatnot.
*Group of people walks by*
Nondescript Group Member: Hey!
Evan: How y'all doin'?
Group: We're good! *walks on*
Zenia: What a bunch of OFP's
Evan: For real though.