Those usually refer to messages sent to the other guy.
Say you have the default setting that allows 3 uploads per user.
Someone browses you, and chooses 4 of your files: the fourth, or a duplicate request, gets the "limit reached" message.
Say they choose 100: a lot of them will get the "greedy" message from you, and your server will ignore any more requests from their client for <don't know how long>
If the client starts a download, then kills it or quits, thus refusing any more packets for that file, you get the notification that the upload was "
interrupted"
There are more variations and cases I'm sure, but you get the idea . . .
For more and better info, watch for posts by sberlin or one of the other developers. The code is always improving, so today's answers might change (I hope so--I'd like to see the greedy request held queued by the client, who would then only send respectful requests)