Ctrl/Z may be used to exit the Edit/FDL utility if you are
    currently at the main level. At lower levels, Ctrl/Z returns
    you to the main level.

    You can use Ctrl/C to exit from the Edit/FDL utility at any
    time. Avoid using Ctrl/Y to abort the Edit/FDL utility because
    that may leave the scrolling region of a DEC_CRT terminal in an
    undetermined state. If this happens, use the DCL EXIT command
    to restore the terminal to its original state. This action is
    unnecessary if the next DCL command issued invokes a new image.

    To get more information about any particular question, type "?"
    and press the Return key. When an invalid response is made to one
    of the FDL Editor's questions, the action taken is equivalent to
    the ? command.