General Header Fields
Cache-Control
Connection
Date
Pragma
Trailer
Transfer-Encoding
Upgrade
Via
Warning
Entity Header Fields
Allow
Content-Encoding
Content-Language
Content-Length
Content-Location
Content-MD5
Content-Range
Content-Type
Expires
Last-Modified
extension-header
Response Header Fields
Accept-Ranges
Age
ETag
Location
Proxy-Authenticate
Retry-After
Server
Vary
WWW-Authenticate
Request Header Fields
Accept
Accept-Charset
Accept-Encoding
Accept-Language
Authorization
Expect
From
Host
If-Match
If-Modified-Since
If-None-Match
If-Range
If-Unmodified-Since
Max-Forwards
Proxy-Authorization
Range
Referer
TE
User-Agent