SPAWN [/qualifier...] [command]

    Creates a subprocess of the current process.  The context of the
    subprocess is copied from the current process.  If 'command' is
    specified, that command will be executed by the subprocess.

Additional information available:

/INPUT/NOLOGICAL_NAMES/NOSYMBOLS/NOTIFY/NOWAIT
/OUTPUT/PROCESS

    Specifies an input file containing one or more command strings to
    be executed by the spawned subprocess.  If you specify a command
    string along with an input file, the command string is processed
    before the commands in the input file.  Once processing is
    complete, the subprocess is terminated.

    Specifies that the logical names of the parent process are not to
    be copied to the subprocess.  The default is that the logical names
    of the parent process are copied to the subprocess.

    Specifies that the DCL global and local symbols of the parent
    process are not to be passed to the subprocess.  The default is
    that these symbols are passed to the subprocess.

    Specifies that a message is to be broadcast to SYS$OUTPUT when
    the subprocess completes or aborts.  The default is that such a
    message is not sent to SYS$OUTPUT.

    Specifies that the system is not to wait until the subprocess is
    completed before allowing more commands to be specified.  This
    qualifier allows you to specify new commands while the spawned
    subprocess is running.  If you specify /NOWAIT, you should use
    /OUTPUT to direct the output of the subprocess to a file to prevent
    your terminal from being used by more than one process simultaneously.

    The default is that the system will wait until the subprocess is
    completed before allowing more commands to be specified.

    Specifies an output file to which the results of the SPAWN operation
    are written.  You should specify an output other than SYS$OUTPUT
    whenever you specify /NOWAIT to prevent output from the spawned
    subprocess from being displayed while you are specifying new
    commands.  If you omit the /OUTPUT qualifier, output is written
    to the current SYS$OUTPUT device.

    Specifies the name of the subprocess to be created.  The default name
    of the subprocess is USERNAME_n.