token and the client may proceed with an HTTP/1.0 (or Keep-Alive)
   persistent connection.

   An HTTP/1.1 server may also establish persistent connections with
   HTTP/1.0 clients upon receipt of a Keep-Alive connection token.
   However, a persistent connection with an HTTP/1.0 client cannot make
   use of the chunked transfer-coding, and therefore MUST use a
   Content-Length for marking the ending boundary of each message.

   A client MUST NOT send the Keep-Alive connection token to a proxy
   server as HTTP/1.0 proxy servers do not obey the rules of HTTP/1.1
   for parsing the Connection header field.






 
RFC 2068                        HTTP/1.1                    January 1997


19.7.1.1 The Keep-Alive Header

   When the Keep-Alive connection-token has been transmitted with a
   request or a response, a Keep-Alive header field MAY also be
   included. The Keep-Alive header field takes the following form:

          Keep-Alive-header = "Keep-Alive" ":" 0# keepalive-param

          keepalive-param = param-name "=" value

   The Keep-Alive header itself is optional, and is used only if a
   parameter is being sent. HTTP/1.1 does not define any parameters.

   If the Keep-Alive header is sent, the corresponding connection token
   MUST be transmitted. The Keep-Alive header MUST be ignored if
   received without the connection token.