security - Is HTTP header Referer sent when going to a http page from a https page?

Question

After a few tests, I'm starting to reach the conclusion that a browser does not send a Referer HTTP header when one clicks to a http page from a https one.

What security reason is that for? Is is defined somewhere in the standard?

Answer 1

The HTTP RFC states, in section 15.1.3 Encoding Sensitive Information in URI's :

Clients SHOULD NOT include a Referer header field in a (non-secure) HTTP request if the referring page was transferred with a secure protocol.

So, this is expected / standard behaviour.