[Harry Putnam asked some questions I can't answer, plus this one.]
| A related question: When using the {INCLUDERC=} line are VAR values
| set in .procmailrc carried over to what ever script is called?
Are you asking about INCLUDERCs or about scripts?
The only value that changes inside an INCLUDERC is that of the pseudovariable
$_ (name of the current rcfile).
As to scripts, procmail exports all regular variables into the environment,
but each executable has its own opinion of what special variables like $#,
$$, $1, $-, and such mean. A lot depends on whether there are characters
from $SHELLMETAS in the action line; if not, procmail substitutes its own
values before calling the executable, but if there are, the shell substi-
tutes *its* values for all variables, and its values for special variables
like those may differ from procmail's.