mahasamatman is absolutely correct. I have found that booking any flight using codeshare results is confusion and errors. Take, for example, seat assignment. On a recent flight (FRA-BLR) that I booked as a codeshare (LH metal, UA flight number, UA paper) the following happened. I had UA assign a seat when I made the reservation. They were able to get an OK seat, but I wanted row 1 of the 747 (front of business class). UA could not get that. So I called LH to see if they could put me up front. They said yes, but because UA had already assigned a seat, they could not change my seat. I called back UA to cancel my old seat, and they said they did. Called back LH, and they said UA still had a seat request so they could do nothing. Called back UA again, and they finally said they could get me 1A. Great, I thought. But then I showed up at the airport, and was given a MIDDLE seat!! (2-3-2 config). Middle of the 3 across. Worst seat in the house! I said I had 1A, but they had no record of it.

From what I hear, this is not an isolated event. The UA and LH systems do not talk together very well. So my advice is RUN from ANY codeshare! Always book the paper on whatever the metal is.