Had a somewhat pleasant surprise. Had an itinerary with UA-TK-RJ, same in reverse. UA booked on UA ticket and TK and RJ booked on a TK ticket, RJ was a codeshare. I chose to credit TK to UA, and their system crapped out and wouldn't save. I requested mileage credit from UA and they gave me credit for the TK and RJ segments. I thought I would only get credit from TK since RJ is part of OW, but guess not. Got mileage based on distance flown and PXM/PQS based on the TK fare class. Is this how it is supposed to work?