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

       /ERROR=filespec

    Defines an equivalence name string of 1 to 63 alphanumeric
    characters for the logical device name SYS$ERROR. The logical
    name and equivalence name are placed in the process logical name
    table for the created process. (The /ERROR qualifier is ignored
    if you are running SYS$SYSTEM:LOGINOUT.)