If I was reading the CBA FAQ correctly, I came up with the following instances:
1 - The right of set-off
2 - if a player is acquired off waivers, the new team assumes the rest of the salary
3 - waived for participation in a prohibited action (drugs, etc)
4 - a contract that is protected by lack of skill and a player is waived by a certain date.
5 - if a team uses the amnesty provision and claiming team submits a bid.