RPL_PROTOCTL (RPL_ISUPPORT):
 version: 2.1+ (new version: 3.1+)
  
 This sends a numeric during client signon that lists various features that
 Unreal supports.  This allows client and script writers to know what features
 they can use, and various parameters about the irc server.  The numeric
 used is '005' to try and maintain some semblance of compatibility with
 DALnet which has a similar feature.  The 005 numeric may be split across
 multiple lines if the length exceeds 512 characters.

 The format is:
  :servername 005 target feature1 feature2... :are supported by this server.
  :servername 005 target feature200... :are supported by this server.

 features are either a word describing the feature eg: 'SILENCE', or a word
 describing the feature and an equals and a list of parameters.  
 eg: SILENCE=15 (says that we support silence, and we support up to 15 of
 them per user), or FOO=12,3 (says we support FOO with parameters 12 and 3)
 for example ircu2.10.08 lists:

 :test.undernet.org 005 test SILENCE=15 WHOX WALLCHOPS USERIP CPRIVMSG 
   CNOTICE MODES=6 MAXCHANNELS=10 MAXBANS=30 NICKLEN=9 TOPICLEN=160
   KICKLEN=160
 
-------------------------------------------------------------------------
UnrealIRCd Supports:

:unreal.server 005 nick MAP KNOCK SAFELIST HCN WATCH=%i SILENCE=%i MODES=%i
                        MAXCHANNELS=%i MAXBANS=%i NICKLEN=%i TOPICLEN=%i
                        KICKLEN=%i CHANTYPES=# PREFIX=%s :are supported by this server

Feature "MAP"
-------------

 /map shows the servers as the server percieves them, who's connected
 to who in a pretty display, with number of users attached to each server

Numerics used:

RPL_MAP (006)
RPL_MAPEND (007)

Feature "KNOCK"
---------------

Command: /KNOCK #Channel :<Reason>

This command will only work if you are not a member of the channel and the
+K (No knocks) mode is not on, and the channel is not +i (and you are not
banned). This will send a notice to ops in the channel, about that the user
"knocked".

Feature "SAFELIST"
------------------


This note means that the user will not get disconnected when doing a /list,
as some IRC networks do

Feature "HCN"
-------------

This is a special feature that you activate using /protoctl +HCN,
that will cause +c notices when being oper, being in the Hybrid IRCd style

Feature "WATCH"
---------------

Parameters: How many watch entries are possible

This will ensure the server is able to do the DALnet WATCH command


Feature "SILENCE"
-----------------
 Parameters: How many silence entries you can have
 Version: unknown, ircu2.9.32 at least.

 Silence is a server side ignore.  You can /silence +hostmask or
 /silence +nick, to add someone to your silence list, or use /silence
 -hostmask to remove it.  /silence will list your 'silence list'.
 you can /silence nick, to see someone elses silence list (useful for
 helping someone).  Silence is preferably used as a last resort as it
 tends to use server CPU time.

 Syntax:
  SILENCE +hostmask
  SILENCE +nick
  SILENCE -hostmask
  SILENCE -nick
  SILENCE nick

 reply:
  RPL_SILELIST      217
  RPL_ENDOFSILELIST 218


Feature/Modifier "MODES"
------------------------
Parameters: How many modes with parameters you can use in one /mode buffer


Feature/Modifier "MAXCHANNELS"
------------------------------
Parameters: How many channels a normal user can join (opers may have
            unlimited)

Feature/Modifier "MAXBANS"