<p>To clarify further, I am asking specifically about the rarely discussed and possibly nonexistent phenomenon of officially published and objective minimum requirements, not any informal or de facto requirements. (It is easy for the topic to drift precisely because of the sorts of issues you mention.)</p>
<p>It would also be very interesting if admissions officers had made unofficial remarks about unpublished but objective requirements, along lines such as “applications below X on the SAT [or academic index calculation, etc] are thrown in the Reject pile with no further reading unless they are children of major sugar daddies to the university”.</p>