Examples include identity or preference information. To maintain parallel terminology with the HTTP State Management Mechanism, I will use the term Pcookie to refer to the state information that passes between a proxy server and client, and that gets stored by the client. This document describes a way to create stateful sessions with HTTP requests and responses. I describe here a way for a proxy server to send state information to its client, and for the client to return the state information to the proxy server. The goal is to have a minimal impact on HTTP clients and proxy servers.
White space is permitted between tokens.
Note that while the above syntax description shows value as optional, most attrs require them. The proxy server initiates a session, if it so desires. To do so, it returns an extra response header to the client, Set- Pcookie. The proxy server may ignore it or use it to determine the current state of the session. Proxy servers may return Set-Pcookie response headers with any response.