Re: idempotence of POST

re: POST with new result header vs. GET-with-body:

I was more concerned about "upgraded client talking to upgraded server
through non-upgraded proxy". All of the proxy servers would have to
upgrade to support GET-with-body, then all of the clients, before any
server could do it.

"POST-with-annotation" would work with old proxies (the result header
would pass through) and with old clients (yes, they'd warn if you hit
'reload', but the INITIAL transaction would work).