Ownership · The custodian · Element
The boundary
What each role decides.
The part
What it is
The owner decides what the data means and who may see it; the custodian decides how it is stored and implements the access decision.
The boundary is where governance most often fails, because a request that falls between them is handled by neither.
The smallest level
The attributes it carries
Each attribute is one of the framework’s shared types. What a date is, and how it is written, is defined once for the whole model — the note here says what it means in this particular place.