The economics · The liability · Element
The outstanding
How much has been earned and not redeemed.
The part
What it is
In units and in value. The value depends on redemption cost and on expected redemption rate.
Tracked over time, since a growing balance is either a growing programme or a redemption problem.
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.