AA - I was booked by my travel agent on IB (Codeshare from Madrid nice flight by the way)..saw there was no seat assignment for the IB portion on AA.com so called to request a seat and was told if I wanted AA to do it they would charge me something like a 7.00 fee otherwise I could either have my agent make the request or call IB myself. Never heard of this before but guess I should get used to it.