-q: quiet mode (does not give you update messages)
-h: displays usage message
-e <email>: log in to server using <email>
-c <jobs>: always try to keep <jobs> cached locally
-x <proxy>: use specified proxy server
proxy format: http://[user[:password]@]http_proxy_address[:port]/
-p <priority>: set process priority


* Valid priorities under Windows systems:
32: Normal priority
64: Low (idle) priority
128: High priority

On XP and Win2K there are additional priorities:
16384: below normal
32768: above normal

Linux priority value range -20 to 20, -20 being highest priority and 20 lowest

Basically if you dont use the -p 16384 switch with 2k and XP the client will run above normal priority and could make your PC hang.