In this case, although I am getting new registrations coming into my email folder at the rate of about 1 every four minutes (even using the Captcha), for simplicity sake let's just say there are 22,002 users.
2 of the users, an admin account and a test user account, I want to keep.
Everything else, I want to delete.
I thought I would mention that detail, in case it is relevant.
I just went back through all the Admin control panel options & sub-options. I see a way to edit permissions a single user at a time.
I was hoping I could edit one of the .php or other files that might contain the list of usernames.
I looked through each of the directories in the "Forum" folder, and opened up some of the bigger files in a text editor. Lots of interesting programming but no user-names.
Where does phpBB store the username list ? I was hoping I could edit some sort of *.ini type of file and accomplish the task that way.