The mechanism · The redemption · Element
The redemption rate
How many members actually redeem.
The part
What it is
A low rate means either the rewards are unattractive or redemption is too difficult, and both are design problems presented as breakage.
It is also the number the liability calculation rests on.
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.