I think I have found an "undocumented feature" as I always called them when I was very active developing.
I have discovered that many of my files have strange characters in the title field. How they got there is unknown. I am using MP3Tag to try and remove them although I am running into a few issues/blockages with the available scripting options.
The "offending characters" are in the title field. They are at the leftmost position and are only displayed as a small, skinny, vertical, rectangle (see screen caps).
I have tried regex, scripting and whatever else I thought might work from MP3Tag.
In the screen caps, I tried $right(%title%,$len(%title%)-1) as well as $right(%title%,$len(%title%)-10). As you can see in the captures, they both did the same thing. Nothing.
I even tried "filtering" to set the list to display only files with those "unknown" characters using regex and even regex could not reference those chars. It's like they are there but they aren't.
So far, I can only remove them manually and there are a substantial amount. I'd love to be able to automate it.
I am using a combination of Picad and MP3Tag to clean up a very large library for a terrestrial and online radio station. They use Station Playlist. Once I finish the tagging, updating and corrections of the files, I run them through the "Track Tool" of SPL. It creates the ReplayGain and the CUE, Seque, etc. points. I also edit the SPL specific fields as needed for classification. It seems when this is done, the strange characters are introduced into various fields.
Time to contact the author of that software and advise him of this happening.