VMS Help CMS, SET, ACL, Qualifiers, /ACL[=(ace[,...])]  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Specifies one or more access control entries (ACEs) to be
    modified. When no ACE is specified, the entire access control
    list (ACL) is affected. Separate multiple ACEs with commas and
    enclose the list in parentheses. The specified ACEs are inserted
    at the beginning of the ACL unless the /AFTER qualifier is used.