construct/help/users/umode

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

User modes: (? designates that the umode is provided by an extension
             and may not be present on this server)

     USERMODE     DESCRIPTION
-----------------------------------------------------------------
         +o     - Designates this client is an IRC Operator.
                  Use the /oper command to attain this.
         +i     - Designates this client 'invisible'.
       ? +h     - Has a cloaked host. May be +x depending on cloaking module
         +g     - "caller id" mode only allow accept clients to message you
         +w     - Can see oper wallops.
       ? +C     - Prevents you from receiving CTCPs other than ACTION.
         +D     - Deaf - ignores all channel messages.
         +Q     - Prevents you from being affected by channel forwarding.
         +R     - Prevents unidentified users that you have not accepted from
                  messaging you.
         +Z     - Is connected via SSL (cannot be set or unset).