Item types
Org-scoped key + field schema + state model + flags. Loan, Alert, Task are types.
An Item type is what specializes the generic Item into a domain noun. It is org-scoped, so each institution defines its own, and it is made of four things: a key (the type's name), a field_schema (the fields that Item carries), a state_model (the states it moves through), and a set of flags.
The flags
The flags decide how the type behaves: workable (does it belong on a Stream?), timeline (does it keep an ordered history?), gates (does it require approval gates?), and record (is it kept as durable data?). A Loan is workable and gated; a logged Decision is record but not workable. Same routes, different flags.
Types you register
Loan, Alert, and Task are types. So are Thought, Decision, and Feedback: the Compounding Loop streams are Item types too, which is why the loop is queryable like everything else. New types are registered as the domain needs them, and schema_version is the compatibility contract that lets a type evolve without breaking the Items already created against it.