Exact Definition of "in the cylinder"

It seems to me that the concept of "in the cylinder"
or "in the imaginary cylinder" is somewhat vaguely
defined. To start with, is the surface of this
imaginary cylinder tangent to the outside or inside of
the rim? Or does it pass through the center of the
rim? Then, for the ball being "in", are we talking
about all of the ball, the center of the ball, or just
some part of the ball? Or, for interference, could we
be talking the point on the ball where the interfering
player made contact with the ball?

I have done some searching and I cannot find what
would appear to be an authoritative answer. I have
seen some references which I do not regard as
authoritative but which would seem to imply that we
are talking about the outside edge of the rim and any
part of the ball, which is about how I had always
tended to regard the concept. However, I ask now
because it seems to me that, the way the rule is
normally interpreted, the _center_ of the ball has to
be in the cylinder before a referee is going to call
goal tending or basket interference. (My inference is
based on frequent occurrences of replaying video in
slow motion when it was close and there was a good
view of it.)

So, is the definition really vague? If not, can
anyone provide a pointer to an authoritative and
complete definition? (It would be interesting based
on either NCAA rules or NBA rules.) If, as many
suspect, the goal tending or interference rules are
supposed to come into effect when _any_ part of the
ball is in the cylinder, can others validate my
observation that enforcement is rarely consistent with
that interpretation? If the enforcement discrepancy
exists, are rule makers concerned with it?

Regards,
David V.

> So, is the definition really vague? If not, can
> anyone provide a pointer to an authoritative and
> complete definition? (It would be interesting based
> on either NCAA rules or NBA rules.) If, as many
> suspect, the goal tending or interference rules are
> supposed to come into effect when _any_ part of the
> ball is in the cylinder, can others validate my
> observation that enforcement is rarely consistent with
> that interpretation? If the enforcement discrepancy
> exists, are rule makers concerned with it?
>
> Regards,
> David V.
>
Here you go:
http://www.ncaa.org/library/rules/2007/2007_m_w_basketball_rules.pdf