Are you treating the filenames which is a property for the OS or the embedded data which is the topic for the program MP3tag?
Perhaps a look at the first steps to use this program helps:
If you want to replace "(Explicit)" with "[E]", then
Select the files that should be treated,
Select from the toolbar "Actions (quick)"
Select an action of the type "Replace"
Select for field _FILENAME from the list or type it in if it is not in the list
Replace with: [E]
Click OK to start the action.
At the moment I'm treating them as part of the file, as I'm just starting with MP3 tag.
So I want to get them into the Embedded data, as I want to have the end result being all my files as
Artist - Title - Genre - BPM - [C] / [E] . file extention.
I am looking for helping getting there from multiple files in different formats.
I have read the discussion around explicit tags, and I really wish by now MP3 files supported them, but they don't natively. Same as Remix as an option.
but I also know that unless you're playing the music publicly and deal with remixes a lot, then the audience for those changes is just pretty much DJ's or people that don't like swearing in their songs.
I did read the guide, but it didn't really cover reading from the filename into another tag (unless I use composer)