[Users] several presence question

Hi! I read the docs of the presence module and have some question. Maybe someone can enlighten me ;-) 1. If I understand correctly, the pua module acts as a "UAC". Thus, it can be used to send PUBLISH or SUBSCRIBE. I wonder what is the usecase for sending SUBSCRIBE? Usually, a client which sends a SUBSCRIBE receives subsequent NOTIFY messages. How can these NOTIFY messages be handled? 2. If an external application sends PUBLISH via the uac_mi interface, how can be distinguished between a "new" PUBLISH or an "update" PUBLISH? For example if the MI interface returns the E-Tag from the 200 Ok response this could be used in the next request to group identify PUBLISH reqeusts which belong together. 3. There is a bug in the pua module docs: the db_url(str) parameter is described twice. 4. The following module documentations lack of default values for the module parameters: pua, pua_usrloc, presence (maybe some example show the default value, but IMO the default value should be explicitely stated) 5. How can I update the presence status from a third party application? Is it possible to write directly into the tables of the presence modules? Or can I fake an update using the pua_mi to loop a PUBLISH to itself for handling it afterwards with handle_publish()? May this cause problems because it interferes the subsequent PUBLISH request from the client (etag)? regards Klaus