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

    Cancels all screen displays (except PROMPT) including the PCA-
    defined PLOT, SOURCE and OUT displays. After canceling all
    displays, you must use the SET DISPLAY command to create new
    screen displays if you want to select them for use in screen mode
    (see SELECT command). If you use the /ALL qualifier, omit the
    display-name list.