The conditions

What would have to change for it to be worth trying again.

The part

What it is

Sometimes an approach failed because of something else that has since changed. Recording the condition keeps the option open rather than closing it permanently.

Without it, a rejected approach is rejected forever, which is occasionally wrong.

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.