From time to time, ExpertFlyer has been adding upgrade/award hidden classes on various carriers. They don't say anything much about why they have access to the carriers they do, and why the don't have access to United. Does anyone know if that's a United thing? Does United consider it proprietary, and therefore refuse to allow third-party access to it? All of which seems pretty silly -- because I'm forever wasting their agents' time by calling to see if there's confirmed upgrade space available on a flight I'm considering. Sure would be nice to just hop on ExpertFlyer...