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

    PQL_MBYTLM sets the minimum buffered I/O byte limit for a process
    created by the Create Process ($CREPRC) system service or the DCL
    command RUN (Process).

    PQL_MBYTLM has the DYNAMIC and GEN attributes.