Conditional naming

Is there any way to keep the name of the file iff the renaming pattern is not fullfilled for that file
Reply to #1:
Hi Jan.
Probably. If you look closely, you'll see a little {if}. It's usually located next to the Apply option. You can enter names patterns there.
Posting examples would be very helpful.

Miguel
Reply to #2:

Hi guys,

I don't understand. If the renaming pattern doesn't match the filename nothing is changed. Maybe I totally don't understand, but I'm thinking the name of the file is *always* kept if the renaming pattern is not fulfilled. (?)

Best,
DF