The fallback plan · The trigger · Element
The watcher
Who checks it, and when.
The part
What it is
A named person and a date. A trigger nobody is scheduled to check does not fire.
Checked before the lead time expires rather than at the point of maximum information.
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.