ReadonlyprimitiveThe primitive Tableau actually drew — 'bar', 'line', 'pie', …
ReadonlyencodingsEvery field on this card's encodings, colour and size included.
Read by nothing today, and mirrored anyway: this is the member whose absence from the old hand-written type is what made "the API cannot tell a stack from a side-by-side" look like a fact about Tableau rather than a fact about our type. Nothing in the contract reports Tableau's Stack Marks setting — there is no such declared member anywhere — so this alone does not settle that question, but it is the evidence any attempt needs.
One marks card of a worksheet's visual specification.
Mirrors
MarksSpecificationinExternalContract/Shared/VisualModelInterface.d.ts. Both members are required there; neither is optional.