If you want to distribute this, I would suggest this:
For text to be mirrored = mirrtext 1
( ) Text will be mirrored
For text not to be mirrored = mirrtext 0
(/) Text will not be mirrored
Using separate raster images for each of the corresponding states of mirrtext. You will have to include the images with the file when distributing. This will eliminate any confusion, as in what is happening to me at the moment.
