I recently was seeking a way to properly determine protocol, under which url request was supplied to the server.
I watched through
[REQUEST_SCHEME] => http
VC9 PHP 5.4.14 TS
It is hard to prove that it is reliable, but it is easy to prove that it is not reliable (if only I could provide a case which it does not work). And I can prove that it is unreliable because it does not work with IIS 7.0 + PHP 5.3