I am looking for a detailed explanation of how Canon's EOS autofocus
lenses can be "adjusted" for focus position or accuracy.  I am
particularly interested in this subject specifically with respect to
Canon's 10D Digital SLR.
I am a little familiar (in an academic sense) with the phase
comparison technology that is employed to do the same in most if not
all of Canon's current SLR's.  What I looking for is some instruction
as to what to can be done to alter the focus position of an otherwise
well-functioning lens-camera equipment pair.  I have heard rumors that
modern SLR's maintain a "database" of focus points for various lenses
or lens focal lengths and that "adjusting" a camera to make focus
properly with a given lens is merely a matter of altering some data in
that database.  If that is so, I would be particularly interested in
finding the software that is used to alter those parameters in a
camera.  On the other hand I have also heard that the adjustment that
is done to "correct" autofocus position problems is mechanical - where
lens elements may be moved relative to each other or where the
autofocus sensors on a camera may be moved.

The simplest "answer" to this question would be a description of a
sure way of obtaining a maintenance manual to the Canon 10D that
describes the procedure required to adjust focus position, along with
whatever software (if any) is necessary to do so.
A less valuable answer may be a more detailed technical description of
what that would make clear "what" could be done - though not
necessarily the "how".  The current price that I have set for this
question is for the latter, less valuable answer.  If you can do
better (the maintenance manual etc.) then I would be willing to double
or triple the amount for this answer.  We can work that out if you
find something.

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Clarification of Question by jcw-ga on 20 Aug 2004 08:56 PDT

Typo - sorry - sentence should be:

"...various lenses or lens focal lengths and that "adjusting" a camera
to focus properly with a given lens..."