Where does Time Machine store its settings? I'm looking for the file that contains all the Time Machine exclusions entered in its Options dialogue. I know that (some of?) the scheduling related settings are stored in the com.apple.backupd-*.plist files at /System/Library/LaunchDaemons but I haven't been able to find the exclusions.
It is in the root directory of the actual backup e.g. /Volumes/Back3/Backups.backupdb/flat/Latest/.exclusions.plist for a machine called flat but that only shows what happened.

More usefully - if you want to edit things see /Library/Preferences/com.apple.TimeMachine.plist

I got the informatiuon from this blog