IRC Advanced

These commands are not likely to be used in day-to-day operations except by delegates (people who have been given special responsibilities who are on IRC), and sometimes not even day to day by them.

These are some of the ones that sometimes don't get remembered. If you're looking for a good general guide for IRC stuff, see the one linked from IRC Help.

invite

Make sure you're allowed to invite to that channel first; this may mean opping up. Syntax: /invite user #channel

OP

If you're allowed to be an op in a channel, you can op yourself. syntax: /msg chanserv op #channel user

Deop

Freenode prefers people don't stay opped up unless they need the ops at that moment. syntax: /msg chanserv deop #channel user

access list

syntax: /msg chanserv access #channel list

access add

syntax: /msg chanserv ACCESS #channel ADD nickname [level]

The level used for antispam tends to be +Aiortv

ban

In case there are problems where talking it out won't do, or temporarily in case of an egregiously misbehaving unattended client: syntax: /mode [#channel] +b <nick!user@hostmask> (no brackets, either square or pointy)

mute/moderated

in case everybody needs to chill the fuck out for a while. Op up first. Voice anyone who needs to be able to talk while all this is going on.

Syntax: /mode [#channel] +m

Voice syntax: /mode [#channel] +v [username]

Syntax for turning it off: /mode [#channel] -m

Devoice syntax: /mode [#channel] -v [username]

http://freenode.net/using_the_network.shtml