Maybe, the biggest obstacle to successfully exploiting
this new library is after those `stacks' are returned.
Unless a user requests all available `items', there is
always a need to translate an actual enumerator into a
relative position within returned stack(s) of results.
So, this patch attempts to bridge that gap by adding a
brief explanation to the existing discussion in Usage.
[ along the way, 'Usage' & 'Caveats' were refactored ]
Signed-off-by: Jim Warner <james.warner@comcast.net>