It's published on Sabre but it doesn't come from there. AA contracts with Sabre (which it used to own) for GDS services. The relevant question is "where exactly does the rule come from?" This gets to the heart of OW mysteries - I have in my mind's eye reps from the major members' revenue desks sitting in a Starbucks in Vancouver tossing ideas back and forth.. "Hey, what if we make people go all the way to Mauritius to get cheap tickets?"

"Ha ha, that's rich. How about requiring a segment to go from JFK to La Guardia?"

"Ha ha, cool..."

Of course that's not really the way this works. I assume.