EXIT - Exits the CMD.EXE program (command interpreter) or the current batch
       script.

EXIT [/B] [exitCode]

  /B          specifies to exit the current batch script instead of
              CMD.EXE.  If executed from outside a batch script, it
              will quit CMD.EXE

  exitCode    specified an exit code as an integer. If /B is specified, sets
              the ERRORLEVEL environment variable to that number.  If quitting
              CMD.EXE, sets the process exit code to that number.

If no exit code is specified, CMD.EXE or the batch file uses the exit code of
the last executed command.