Library /sys$common/syshlp/acledt.hlb ACE_FORMAT  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    An access control list entry (ACE) consists of a series of fields
    started and ended by parentheses. The first field indicates the
    type of ACE to be entered. The second field indicates any options
    that apply to the ACE. The third field indicates the type of
    access to grant or to be monitored (if applicable). In addition,
    the second and third fields have several subfields for the actual
    options and access types, respectively.

    The general format for an ACE is as follows:

     (type, option_flags, access_to_grant)