[stunnel-users] Verify Question

I'm sure that people have asked this question before, but i cannot find a way to search the archives.

What is the difference between verify = 2 and verify = 3, The docs indicate that with verify = 3it will check against locally installed certs, but what does that mean, if I use =2 then what does it verify the cert against?

Also a second question: I'm pretty sure that the answer is no but is it possible to do the following, have a cert A that is signed by CA cert B which itself is singed by a self-signed cert C. If the clients has C installed as a trusted cert, and it received A, is there anyway for it to validate A.

I realize that these are probably pretty novice questions so I really appreciate your patience, thanks!