The Accept-Ranges header, which specifies the range that is accepted by the server.

The Age header, which specifies the time, in seconds, since the response was generated by the originating server.

The Allow header, which specifies the set of HTTP methods that are supported.

The Cache-Control header, which specifies caching directives that must be obeyed by all caching mechanisms along the request/response chain.

The Connection header, which specifies options that are desired for a particular connection.

The Content-Encoding header, which specifies the encodings that have been applied to the accompanying body data.

The Content-Langauge header, which specifies the natural language or languages of the accompanying body data.

The Content-Length header, which specifies the length, in bytes, of the accompanying body data.

The Content-Location header, which specifies a URI from which the accompanying body can be obtained.

The Content-MD5 header, which specifies the MD5 digest of the accompanying body data, for the purpose of providing an end-to-end message integrity check.

The Range header, which specifies the subrange or subranges of the response that the client requests be returned in lieu of the entire response.

The Content-Type header, which specifies the MIME type of the accompanying body data.

The Date header, which specifies the date and time at which the response originated.

The Etag header, which specifies the current value for the requested variant.

The Expires header, which specifies the date and time after which the accompanying body data should be considered stale.

The Keep-Alive header, which specifies a parameter to be used to maintain a persistent connection.

The Last-Modified header, which specifies the date and time at which the accompanying body data was last modified.

The Location header, which specifies a URI to which the client is redirected to obtain the requested resource.

The Pragma header, which specifies implementation-specific directives that might apply to any agent along the request/response chain.

The Proxy-Authenticate header, which specifies that the client must authenticate itself to a proxy.

The Retry-After header, which specifies a time (in seconds), or a date and time, after which the client can retry its request.

The Server header, which specifies information about the originating server agent.

The Set-Cookie header, which specifies cookie data that is presented to the client.

The Trailer header, which specifies that the indicated header fields are present in the trailer of a message that is encoded with chunked transfer-coding.

The Transfer-Encoding header, which specifies what (if any) type of transformation has been applied to the message body.

The Upgrade header, which specifies additional communications protocols that the client supports.

The Vary header, which specifies the request headers that are used to determine whether a cached response is fresh.

The Via header, which specifies intermediate protocols to be used by gateway and proxy agents.

The Warning header, which specifies additional information about that status or transformation of a message that might not be reflected in the message.

The WWW-Authenticate header, which specifies that the client must authenticate itself to the server.