Library /sys$common/syshlp/dbg$help.hlb DEBUG, CANCEL, DISPLAY, Description  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    When a display is canceled, its contents are permanently lost,
    it is deleted from the display list, and all the memory that was
    allocated to it is released.

    You cannot cancel the PROMPT display.

    Related commands:

       (SHOW) DISPLAY
       (SET,SHOW,CANCEL) WINDOW