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

    PQL_DDIOLM sets the default direct I/O limit for a process
    created by the Create Process ($CREPRC) system service or the
    DCL command RUN (Process).

    PQL_DDIOLM has the DYNAMIC and GEN attributes.