when I was working at Boeing Flight Test I had a yellow card that said something like "Authorization for Non-Routine Operations" ... I was on vacation in Mexico, and in my long-ago high-school Spanish tried to tell the Mexicana flight crews (727-200, MEX<-->ACA) about my job ... they let me ride the jump seat

on the way home I chatted up the crew on a Pan Am L-1011-500 (MEX-IAH) with the same result