review source platform
Where one review came from — the storefront itself (first party), or a syndicated platform (Google, Trustpilot, Yotpo, Amazon). A qualifier of the review property; a filterable provenance facet, so a token from a growing vocabulary. Distinct from seller type: this is the review's origin, not the seller's.
Review source platform is answered with one word chosen from the review source platforms list — the same word shared across every product that uses it.
It is a qualifier of review — it has meaning only inside a review statement, one per statement, never on its own. It belongs with review to social proof — what buyers and critics say about it.
It is answered inside every review statement, not as a standalone question on a kind.
Answered inside every review statement — not a standalone slot on any kind.