What is the semantics of the double slash following the scheme in a URI?

Question

According to http://tools.ietf.org/html/rfc3986 and http://en.wikipedia.org/wiki/Uniform_resource_identifier, a URI may or may not contain a double slash following the schem

Answer 1

Well, if you want a "conclusive answer", I think nothing is more conclusive than the official HTTP RFC document (see point 3.2.2 which talks about the HTTP URL scheme).