MODE <nick> <+|-><modes>

Usermodes: (* designates that the umode is oper only)

     USERMODE     DESCRIPTION
-----------------------------------------------------------------
         +o     - Designates this client is an IRC Operator.
                  Use the /oper command to attain this.
         +i     - Designates this client 'invisible'.
       * +w     - Can see server wallops.
         +W     - User is connected using a webirc gateway.
       * +z     - Can see oper wallops.
       * +l     - Can see oper locops (local wallops).
       * +c     - Can see client connections and exits.
       * +u     - Can see unauthorized client connections.
       * +j     - Can see 'rejected' client notices.
       * +k     - Can see server kill messages.
       * +f     - Can see 'I-line is full' notices.
       * +F     - Can see remote client connection/quit notices
         +x     - User's host has been spoofed by services.
                  This mode can be set by servers and services only.
       * +y     - Can see stats/links/admin requests to name a few.
       * +d     - Can see server debug messages.
       * +n     - Can see client nick changes.
         +r     - User has been registered and identified for its nick.
                  This mode can be set by servers and services only.
         +R     - Only registered clients may message you.
       * +s     - Can see generic server messages and oper kills.
         +S     - Client is connected via SSL/TLS
       * +e     - Can see new server introduction and split messages.
       * +b     - Can see possible bot / join flood warnings.
       * +a     - Is marked as a server admin in stats p/o.
         +D     - "deaf": don't receive channel messages
         +G     - "soft caller id": block private messages from people not on
                  any common channels with you (unless they are /accept'ed)
         +g     - "caller id" mode: only allow /accept clients to message you
       * +H     - Operator status is hidden to other users.