When this mode is set together with +i, all channel members can influence who can join.
</para>
</sect2>
<sect2>
<title>+i, invite only</title>
<para>
When this cmode is set, no client can join the channel unless they have an invex (+I) or are
invited with the INVITE command.
</para>
</sect2>
<sect2>
<title>+I, invite exception (invex)</title>
<para>
This mode takes one parameter of the same form as bans. Matching
clients do not need to be invited to join the channel when it is invite-only (+i).
</para>
<para>
Only channel operators can see +I changes or request the list.
</para>
</sect2>
<sect2>
<title>+j, join throttling</title>
<para>
This mode takes one parameter of the form <replaceable>n</replaceable>:<replaceable>t</replaceable>, where <replaceable>n</replaceable> and <replaceable>t</replaceable> are positive integers. Only <replaceable>n</replaceable> users may join in each period of <replaceable>t</replaceable> seconds.
</para>
<para>
Due to propagation delays between servers, more users may be
able to join (by racing for the last slot on each server).
</para>
</sect2>
<sect2>
<title>+k, key (channel password)</title>
<para>
Taking one parameter, when set, this mode requires a user to supply the key in order to join
the channel: /JOIN #channel key.
</para>
</sect2>
<sect2>
<title>+l, channel member limit</title>
<para>
Takes one numeric parameter, the number of users which are allowed to be in the channel before
further joins are blocked.
</para>
<para>
Due to propagation delays between servers, more users may be
able to join (by racing for the last slot on each server).
</para>
</sect2>
<sect2>
<title>+L, large ban list</title>
<para>
Channels with this mode will be allowed larger banlists (by default,
500 instead of 50 entries for +b, +q, +e and +I together).
Only network operators may set this mode.
</para>
</sect2>
<sect2>
<title>+m, moderated</title>
<para>
When a channel is set +m, only users with +o or +v on the channel can send to it.
</para>
<para>
Users can still knock on the channel or change their nick.
</para>
</sect2>
<sect2>
<title>+n, no external messages</title>
<para>
When set, this mode prevents users from sending to the channel without being in it themselves.
This is recommended.
</para>
</sect2>
<sect2>
<title>+o, channel operator</title>
<para>
This mode takes one parameter, a nick, and grants or removes channel
operator privilege to that user. Channel operators have full control
over the channel, having the ability to set all channel modes except
+L and +P, and kick users.
Like voiced users, channel operators can always
send to the channel, overriding +b, +m and +q modes and the
per-channel flood limit.
In most clients channel operators are marked with an '@' sign.
</para>
<para>
The privilege is lost if the user leaves the channel or server
in any way.
</para>
<para>
Most networks will run channel registration services (e.g. ChanServ)
which ensure the founder (and users designated by the founder) can
always gain channel operator privileges and provide some features
to manage the channel.
</para>
</sect2>
<sect2>
<title>+p, paranoid channel</title>
<para>
When set, the KNOCK command cannot be used on the channel
to request an invite, and users will not be shown the
channel in WHOIS replies unless they are on it.
Unlike in traditional IRC, +p and +s can be set together.
</para>
</sect2>
<sect2>
<title>+P, permanent channel</title>
<para>
Channels with this mode (which is accessible only to network operators) set will not be destroyed
when the last user leaves.
</para>
<para>
This makes it less likely modes, bans and the topic will be lost and
makes it harder to abuse network splits, but also causes more
unwanted restoring of old modes, bans and topics after long splits.
</para>
</sect2>
<sect2>
<title>+q, quiet</title>
<para>
This mode behaves exactly like +b (ban), except that the user may still join
the channel. The net effect is that they cannot knock on the channel,
send to the channel or change their nick while on channel.
</para>
</sect2>
<sect2>
<title>+Q, block forwarded users</title>
<para>
Channels with this mode set are not valid targets for forwarding. Any attempt to forward to
this channel will be ignored, and the user will be handled as if the attempt was never made (by
sending them the relevant error message).
</para>
<para>
This does not affect the ability to set +f.
</para>
</sect2>
<sect2>
<title>+r, block unidentified</title>
<para>
When set, this mode prevents unidentified users from joining.
</para>
</sect2>
<!-- not planned (jilles)
<sect2>
<title>+R, quiet unidentified</title>
<para>
When set, this mode prevents unidentified users from sending to the channel, although they can
still join.
</para>
<para>
Please note that this mode is not implemented in Charybdis 1.0.x, and is documented in
expectation for upcoming Charybdis 1.1.
</para>
</sect2>
-->
<sect2>
<title>+s, secret channel</title>
<para>
When set, this mode prevents the channel from appearing in the
output of the LIST, WHO and WHOIS command by users who are not on
it. Also, the server will refuse to answer WHO, NAMES, TOPIC and
LIST queries from users not on the channel.
</para>
</sect2>
<sect2>
<title>+t, topic limit</title>
<para>
When set, this mode prevents users who are not channel operators
from changing the topic.
</para>
</sect2>
<sect2>
<title>+v, voice</title>
<para>
This mode takes one parameter, a nick, and grants or removes voice
privilege to that user. Voiced users can always send to the channel,
overriding +b, +m and +q modes and the per-channel flood limit.
In most clients voiced users are marked with a plus sign.
</para>
<para>
The privilege is lost if the user leaves the channel or server
in any way.
</para>
</sect2>
<sect2>
<title>+z, reduced moderation</title>
<para>
When +z is set, the effects of +m are relaxed. For each message, if that message
would normally be blocked by moderation, it is instead sent to all channel operators. This is intended for use in moderated debates.
</para>
<para>
Note that +n and channel bans/quiets are unaffected by this. To silence a given user completely,
