Currently you use 1 line for 1 sub. Couldn't 1 line be used for multiple subs ending in the same value?
In other words:
Current:
Sub ; Result
---------------------------
Not Rated; NR
no rating; NR
N.R.; NR
New:
Result Sub(s)
----------------------------
NR; Not Rated;no rating;N.R.
Put what you want the final result to be as the first item and then everything after that on that line will modify to the first item (result.) All SUB values (not the result value) should be case insensitive.
It may not make sense to some to change to this method but there are other apps that rename that use this same format. I found one of mine from a couple years ago where I had already added 100's of band name fixes. I would love to use this file for my music library and NOT have to redo it all again. Sounds a bit selfish on my part...I know...but hey, never hurts to ask!

Greg