Not sure how true this is but was told, when I settled a lunch bill at the Officers' Mess at Shawbury recently, that any stay, inluding duty, in excess of 24 hours would incur full charges for the mess (food and accommodation) which would be taken from your pay.
If this is true, how palatable will it become particularly when they are just about to increase ICSC to 8 weeks for example.
Like I said, I am not sure of the accuracy of the comments. Any HR/ Policy pruners out there who can validate this?