Hi. I think the fact that when updating (PUT), we may send only the updated xml elements violates following. http://www.ics.uci.edu/~fielding/pubs/dissertation/rest_arch_style.htm ------8<------8<------8<------8<------ Figure 5-2: The client-server style 5.1.3 Stateless We next add a constraint to the client-server interaction: communication must be stateless in nature, as in the client-stateless-server (CSS) style of Section 3.4.3 (Figure 5-3), such that each request from client to server must contain all of the information necessary to understand the request, and cannot take advantage of any stored context on the server. Session state is therefore kept entirely on the client. ------8<------8<------8<------8<------ Am I right? If so, this is quite huge violation. Much much bigger than some state of SESSION_ID/TOKEN. Would caches/proxies work well with current design? Jaroslav Henner.