rpmbuild debuginfo strip Qs: how to control, which revs?

[Matt England <mengland mengland net>]

I am building that some of my rpmbuild's on various machines/platforms 
strip the debuginfo from the rpms (and make the additional "debuginfo" 
.rpm) and some don't.

I get the impression from a little web searching that this debuginfo 
feature was introduced in some version in the lifetime of rpmbuild, but I 
can't find any official docs on this so far.

In any case, I want to use the debuginfo-stripping gizmo on all my 
builds.  What things to I need in place to make this happen?  rpmbuild 
--version above a certain version?  Is there an rpmbuild cmdline switch for 
which I can specify whether or not to strip debuginfo and make the 2nd 
"debuginfo" .rpm?

-Matt