/hop is not an IRC command on most (all?) IRCd's, it's a function built into mIRC (and perhaps some other chat programmes)
/debug @Raw:
-> qld-chat.bigpond.com PART #Help.Services
-> qld-chat.bigpond.com JOIN #Help.Services
<- :Watchdog!CN@=rlAXM-539-378-107-039.nsw.bigpond.net.au PART #Help.Services
<- :Watchdog!CN@=rlAXM-539-378-107-039.nsw.bigpond.net.au JOIN :#Help.Services
-> qld-chat.bigpond.com MODE #Help.Services
<- :ChanServ!RoomService@ircservices.bigpond.com MODE #Help.Services +o Watchdog
<- :qld-chat.bigpond.com 324 Watchdog #Help.Services +enrtL
<- :qld-chat.bigpond.com 329 Watchdog #Help.Services 1055390768
See the PART then JOIN...
Some IRCd's may have a command "/hop" for something or other which may be an oper-only command.
