I believe they are used for multiplayer - to allow your model and animations to be sent to the other players, and theirs to be sent to you, so you will see what they are actually flying. So you can see a Mustang in the appropriate colors, rather than a baby blue C172 booming along at 350 kts. It would also appear from those lines that if you don't have their model or texture package (they are flying a payware package that you don't own), you could receive it, but I'm positive that that is not the case - it probably just sends the title and variation information with the position and other info used in multiplayer.
Brian