I Searched and found the post I referred to above. Here is the relevant information,

Q. Am I allowed to credit the artists who played the RealTracks on my CD if I want to?

A (from PGM). We actually request that you do not credit any RealTracks or MIDI Soloist artists in order to maintain the artist's creative integrity.


And here is the original post,

https://www.pgmusic.com/forums/ubbthreads.php?ubb=showflat&Number=179419


This is a resolved issue from at least 7 years ago!