supporting properties

Finally I got some time to go over the email discussions. Thanks very 
much for the detailed explanations you've all provided upon my request 
for clarification.

My understanding is that 'supporting properties' is a mechanism to 
allow different portlets to share a common persistent state. Portlets 
could modify this common persistent state. Other portlets will get the 
updated common persistent state on the next WSRP (action/markup) 
operation. There are no special calls triggered to the portlet because 
the common persistent state has changed.

Are my assumptions correct?

Alejandro