Thanks for your reply.
Yes, they are singles.
I made a mental note of the wiring order and was then "distracted" by a phone call. I already had the red one in "common" where the old one was but then started to doubt about the other two. I am pretty sure that the way I did it in the end...
I am replacing an old two-way light switch with a new one. The 3 wires coming out of the old one are Red, red and yellow. One red went to C at the top but I cannot recall where the other two went. I have put the yellow in L1 and the red in L2 and it works fine. Can anyone confirm that it is ok...