The Note Kind is pretty central to the Chandler content model. We envision the Note as an embryonic item, a thing that the user can quickly create and start typing or pasting into, then turn into an email, task or event, as described in CreatingNewItemsWorkflow. Alternately, the user could just leave it as a Note and still be able to assign it an importance and processing status so that it works in the Processing workflow and the Dashboard view (PPFInformationDesign). Finally, a note is the model for the base item that can be "stamped" as a task, email, event or any combination of the above, as described in EndUserStampingModelSpec.

A Note isn't exactly the only kind of user data object, however -- there is some user data that doesn't have a processing status, like a Contact. So Contact wouldn't be a sub-kind of Note. We'll take a look at Resource Items some day (things like slide decks, spreadsheets, word processing documents) and decide whether or not they're more like processing items (sub-kind of Note) or more like Contacts (not a kind of Note).

So here's the Content Model for user content for 0.4:

This is roughly implemented so far, and the Stamping GUI stuff is being built on top of that.