The SPAWN command can be used to either issue a single DCL
    command from within PMDF QM or to leave PMDF QM temporarily, do
    other work (e.g., type out a file, generate a directory listing,
    etc.), and then return to PMDF QM.

    By default, the context of the current process is copied to the
    subprocess. This behavior can be controlled with the /LOGICAL_
    NAMES and /SYMBOLS qualifiers.