(Note that escapes are only recognized immediately after newline.)
    ~?  - this message

    Supported escape sequences:
      ~.  - terminate connection (and any multiplexed sessions)
      ~B  - send a BREAK to the remote system
      ~C  - open a command line
      ~R  - Request rekey (SSH protocol 2 only)
      ~^Z - suspend ssh
      ~#  - list forwarded connections
      ~&  - background ssh (when waiting for connections to terminate)
      ~?  - this message
      ~~  - send the escape character by typing it twice
    (Note that escapes are only recognized immediately after newline.)