Sizing · The build-up · Element
The price
What they would pay per purchase.
The part
What it is
Realised price rather than list, and the price of the thing being sized rather than of the whole relationship.
Where price varies by segment, sizing at a single average produces a number that describes no actual segment.
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.