Sponsored placement / ranking provenance on catalog search results — in scope?

[archerII]

I'm evaluating UCP for a buyer-side agent that shops on behalf of a user with an explicit ranking preference (e.g., "camera quality matters more than brand").

Before asking, I checked docs/specification/catalog/search.md and the search request/response scaffolds: the only ranking-related language I found is that filter-only queries return products "without text-relevance ranking," and I couldn't find any field marking a result as sponsored, boosted, or otherwise commercially incentivized. Apologies if I missed it in another schema.

Three concrete questions:

1. Is there a field (current or planned) exposing sponsored/paid placement or ranking provenance on catalog search results?
2. If such metadata exists or gets added, would it be normative (MUST when applicable), or optional — i.e., could a conformant business omit it while returning commercially influenced ordering?
3. Is there any mechanism for the buyer-side agent to request a neutral ordering (or to learn what the ordering criterion was), or is result ordering entirely business-defined and opaque by design?

Context for why I'm asking: an agent that picks the top-ranked result satisfying its hard constraints will systematically absorb the business's ranking preferences into what looks like a neutral choice. If ranking incentives aren't machine-readable, the agent can violate its user's stated preference order without any protocol violation on either side. I'd like to understand whether that is considered in scope for UCP's catalog capability, or intentionally left to marketplace regulation / implementer policy. Either answer helps.