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

    (VAX only) SWPALLOCINC sets the size (in blocks) to use to back
    up swap file space allocation in the swap or page file. Space in
    the file is allocated in multiples of this unit (up to WSQUOTA)
    to guarantee swap space.

    This special parameter is used by Compaq and is subject to
    change. Do not change this parameter unless Compaq recommends
    that you do so.