rack/rack — pull request #352 by jordansissel (2012-02-28 21:03:19+00:00)
Title: Include link to RFC3875 (CGI 1.1 specification)

... and the section describing how headers are to be translated into HTTP_xxx names.

This link defines important behaviors not described in the Rack SPEC, including:

* dash to underscore translation
* uppercase-ness
* that multi-value headers must be rewritten to single-value with the same semantics (presumably as described in RFC2616 section 4.2)