I'm not sure about this...will mark it for the PM to comment.
Yes and No :)
So you can setup ranges we scan so you can exclude your DHCP ranges
You cannot do the latter.
What you can do is when the scheduled discoveries run, if there are items you don't care about and don't want us to ever tell you about them again, you can add them to an ignore list.
While that method works for smaller networks and sites, it can get to be pretty challenging with 300 offices, and 12,000 nodes. We'll continue playing with it. Our primary need is for a way to detect unauthorized wireless APs, computer systems configured in bridging or routing mode, or new, unauthorized network edges.