2.2.2 The Persistent-Auth Response Header
If the server successfully authenticates the request, it MAY indicate whether the Authorization header will be required for the next request on the connection. This is part of performance optimization and does not guarantee that an Authorization header will or will not be required.
The Persistent-Auth header has the following grammar:
Persistent-Auth = "Persistent-Auth" ":" 1#(persistent-auth-token) persistent-auth-token = token
The Persistent-Auth-token has two possible values: "true" and "false". The client behavior in response to this header is specified in section 3.2.5.