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
Search: (Explicit)
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)
into title and then filter for titles that have "explicit".
For all these files I would then fill the correct field with data and delete "Explicit" from TITLE.
After you have filled the tags with data, it will be very easy to rename the files to a consistent pattern - so I would not worry now about the filename as that would be renamed in a later step.