/sys$common/syshlp/helplib.hlb PIPE, Description, Improving Subprocess Performance  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    A PIPE command can generate a number of subprocesses during
    execution. Often, the applications invoked by command sequences
    do not depend on the process logical names and symbol names.
    In this case, the spawning of subprocesses can be accelerated
    by using the /NOLOGICAL_NAMES and /NOSYMBOLS qualifiers, which
    suppress the passing of process logical names and symbols to the
    subprocesses created by the PIPE command.