[CentOS] how is "binary compatibility" determined?

Hi all!

We've seen quite a few references on the list to "100% binary
compatibility with upstream".  What I am curious about is, how precisely
is this determined?  All the ways I can think of for comparing how two
systems might work seem flawed in some way (e.g., using some sort of
checksum; unit testing; verifying build parameters).  I did some
searches both at centos.org and google, but couldn't find anything
specific about the test(s) used to determine compatibility.

I have no particular reason for asking, other than wanting to be able to
explain it to others if someone asks me.

--keith


-- 
kkeller at wombat.san-francisco.ca.us