In the help they say:
I found those parameters quite surprising. That kind of format is a lot "unix-like".The window titles are not pure filenames. TortoiseSVN treats that as a name to display and creates the names accordingly. So e.g. if you're doing a diff from a file in revision 123 with a file in your working copy, the names will be filename : revision 123 and filename : working copy.
For example, with ExamDiff Pro:
C:\Path-To\ExamDiff.exe %base %mine --left_display_name:%bname --right_display_name:%yname
I substituted them with /dn1: and /dn2: and I got what I was looking for.
For the sake of curiosity I also tried the suggested command line and, with my great surprise, it worked!
Just wondering: does EDP support also some Unix-like parameters? For backward compatibility?
The help says nothing about it.