I know the Navy has done this for years.
Within the last 2-3 years, I had a Finance guy point me toward the JFTR, and prove it was not allowed.
Don't shoot the messenger: I'm simply told that we cannot do this in the AF.
I'm not a Finance/JFTR expert, and maybe he was wrong when it comes to Dept of the Navy. More power to y'all if you can do that.
I do know that all of our XC's at Beale AFB have been terminated UFN.
I've also heard that the AF Training Command is minimizing cross countries, and I believe someone posted on another web site that the only overnight stops allowed are the 4 pilot training bases.
Independent of the what the JTFR says, it was a pretty common practice within the TRACOM. While I was there, it was normal for IPs to take studs on the road and both would either get a) per diem only, b) per diem and one room at a government rate to share, c) per diem and Q rooms only or d) per diem and a room for each person. It would depend on when in the FY it was and how much money the squadron had.