is there a way to remove format strings

mp3tag stores the format strings when converting filenames to tags or tags to filenames.
Over Time this list grows and I would like to delete some of the entries.
Is there a way to remove obsolete format strings?

I usually use $num(%track%,2)--%title% for converting tags to filenames.
For compilations with multiple CDs I use a scheme like 1$num(%track%,2)--%title% for CD1, 2$num(%track%,2)--%title% for CD2 and so on.
Lately I used 2$num(%track%,2)--%title%-(bonus).
Now, when I want to rename CD2 filenames by manually inserting a 2 in front of my standard format "$num(%track%,2)--%title%" some automagic always changes the format string to 2$num(%track%,2)--%title%-(bonus).
This is very annoying as I now have to double check every format before applying it.

Try the [Shift+Del] keyboard shortcut.

Kind regards,