--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/doc/book/en/devrepo/repo/sessions.rst	Fri Apr 23 17:31:46 2010 +0200
@@ -0,0 +1,27 @@
+.. -*- coding: utf-8 -*-
+
+Sessions
+========
+
+There are three kinds of sessions.
+
+* `user sessions` are the most common: they are related to users and
+  carry security checks coming with user credentials
+
+* `super sessions` are children of ordinary user sessions and allow to
+  bypass security checks (they are created by calling unsafe_execute
+  on a user session); this is often convenient in hooks which may
+  touch data that is not directly updatable by users
+
+* `internal sessions` have all the powers; they are also used in only a
+  few situations where you don't already have an adequate session at
+  hand, like: user authentication, data synchronisation in
+  multi-source contexts
+
+.. note::
+  Do not confuse the session type with their connection mode, for
+  instance : 'in memory' or 'pyro'.
+
+[WRITE ME]
+
+* authentication and management of sessions