+Plugins and features of the binder need to keep track of the client
+instances. This of importance for plugins running as service
+because they may have to separate the data of each client.
+
+For common HTML5 browser running an HTML5 application.
+
+### Exchanging tokens
+
+At start, the framework communicates a common secret to both the binder
+and its client: the application. This initial secret is the
+initial token.
+
+For each of its client application, the binder manages a current active
+token. The initial token is the default active token. It is the expected
+token for new clients.
+
+