/sys$common/syshlp/helplib.hlb INITIALIZE, Qualifiers, /ACCESSED  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /ACCESSED=number-of-directories

    Affects Files-11 On-Disk Structure Level 1 disks only.

    Specifies that, for disk volumes, the number of directories
    allowed in system space must be a value from 0 to 255. The
    default value is 3.