If the "Returned" values of ERRORLEVEL are the same for both the
COMMAND /C and CALL invocations, you probably have an IBM 3.3x DOS
running, whereas on at least one COMPAQ I tested, the values are
indeed different!

Ok, now lets see what happens when we try to use the environment to
pass information BACK from within a CALLED module, using first
COMMAND /C and then CALL.

We begin by setting the environment variable "RETCODE" to null,
and then we invoke CALLX0.BAT to change the value.

Then we do the same thing again, using CALL rather than COMMAND /C to
invoke CALLX0.BAT.