The mix · The split · Element
The classification
Which channels count as which.
The part
What it is
Some channels do both and should be split rather than assigned wholly to one side.
The classification is where the argument happens, and settling it once prevents a recurring dispute about what counts.
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.