A few years ago, BOS had an AA Flagship Lounge that could be used by top-tier (Executive Platinum) flyers on international itineraries even if their next flight on that itinerary was domestic. There was an EXP consultant, a frequent poster here once, who flew a lot of trans-cons. He'd buy refundable tickets from his California destination to somewhere in Asia so he could claim to be on an international trip, then cash them in. On the return, he'd do the same with a ticket from Boston to London or Paris.

AA was onto his game, everyone on the EXP desk knew about it, but his business (typically paid F domestically with a trans-con every few weeks, plus some real international paid J or F) was worth so much that they let him keep playing. Didn't cost them much, and it kept a valuable customer happy.