_EXPANSION returns the current expansion mode (i.e., SETDOS /X). It returns the string 0 if everything is enabled, or a string of up to 9 characters of the disabled modes.


For example, if you disable nested variable expansion and redirection:


setdos /x-46


then %_expansion will return 46.


Note that %_expansion will return %_expansion if you turn off variable expansion (setdos /x-3)!