This bathroom talk reminds me of an old Married with Children episode where Al Bundy was building a "man's" bathroom designed with 4 rolls of toilet paper holders. Anyway, the int'l F lavatory is what I imagine when referring to "F" latrines, where, if one were inclined (I'm certainly not but to each his own), after dinner a pax can take a magazine, stroll in there, and leisurely take care of business with ample room.