As I was editing my profile I noticed on the display options pages there are three check boxes with no text saying what they are for.
Those are entries for the ANPOOP mod (All New Messages On One Page).
1 = Make the username a link to the user profile
2 = Allow replies to the ANPOOP messages
3 = Moderate IP addresses
The last one is a mystery to me.
Problem solved: The language file is now properly read, so you can now see what the options mean.