yawor, one of the forum administrators, often recommends to use TV setup code 2051, which is for a Samsung TV. On that code both v1 and v2 work really well. It uses NECx2 protocol which seems to be the best suited one to work together with Flirc.
Using 2051 for my URC-7140 the forward button was left without any function. I asked customer support of OneForAll and the sent me the list attached to this post.
So in case anyone has to assign a function to a remote key manually you can do this using the list.
Another code which worked flawlessly for me was "DVD - 2832", which is for a Toshiba DVD Player. As Toshiba is a japanese company it should use some kind of NEC protocol.
Three or four buttons were left without function and OFA customer support send me a corresponding list for this remote, too.
Thanks a lot to Flirc, especially yawor, and OneForAll for their great customer support !