All normal ASCII text characters are displayed in the viewport.
    Some ASCII control characters can be used for formatting (see the
    following table) while other control characters are ignored.

    Control Key   Formatting Function

    Delete        Deletes the previous character
    Line Feed     Deletes the previous word
    Return        Starts a new line in the viewport
    Tab           Advances to the next tab stop
    Ctrl/G        Sounds the bell at both your terminal and the
                  terminal of anyone linked to the current Phone
                  conversation
    Ctrl/L        Clears all text from the viewport
    Ctrl/Q        Allows normal receiving of characters. Ctrl/Q also
                  negates a Ctrl/S
    Ctrl/S        Freezes the characters currently on screen
    Ctrl/U        Clears the current viewport line
    Ctrl/W        Refreshes the entire screen
    Ctrl/Z        Equivalent to the HANGUP command if used during
                  a conversation; equivalent to the EXIT command if
                  used when no conversation is in progress