A very simple namespace contaning display hints for the content in a message. Can be used for person-person collaboration, or by a service managing notes.

Normal messages are sent, with a sharednote namespace extending them hinting to any supporting client on how to display the message as a note instead. Any changes to the note within that client should then be sent back to the sender, either automatically or when the user saves the note (depending on the update element, by default on a save action by the user).

Any element not specified in the note should use the last known setting or client defaults, so that when a change is sent, only the changed elements are returned.

Each thread is a different shared note. Auto updates should use an internal client timer and batch large changes into chunks, when the user is typing every 5-10 seconds or so. When the user has made changes that haven't been sent and an update comes in on the same thread the client should prompt the user with the changes offering to replace or save their changes.