Most Trade Exceptions cannot be combined, though.
http://members.cox.net/lmcoon/salarycap.htm#72
Quote:
If a team has Traded Player exceptions from two previous non-simultaneous trades, then they can't combine them into one big Traded Player exception. For example, suppose in the last year a team traded a $5 million player for a $4 million player (generating a $1.1 million Traded Player exception) and separately traded a $3 million player for a $1 million player (generating a $2.1 million Traded Player exception). They cannot now combine the two into a $3.2 million Traded Player exception).