Secret No Foreign!!
I'm currently on exchange with the US Navy, responsible for writing all the maritime helicopter (SH/MH-60 series) tactics manuals. The big joke here is that the manuals are all classified NOFORN (No foreign!) so technically I'm not allowed to to look at the books I oversee or practice the tactics in them because I don't know what is in them because I'm not allowed to read them even though I've written them. Makes the job a tad interesting!!