Library /sys$common/syshlp/pca$help.hlb SET, DISPLAY, Qualifiers, /REMOVE  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Creates a display that does not appear on the screen. Although
    a removed display is not visible on the screen, its definition
    still exists, and you can request that it be displayed by using
    the DISPLAY command.