The forward query a federation broker emits on a distributed operation differs substantially between **split-entities** and **no-split** mode (e.g. `?id=<list>&pick=…` vs `?type=…&pick=…`), so a TC asserting one shape rejects a conformant broker running the other. - Consensus (API call, 9 June): `attrs` must **not** be forwarded; `pick` carries the registered attributes; `q`/`type` are evaluated locally on the merged result. - The suite should exercise **both** modes. - Proposal (KZ): add an HTTP header to select the broker's mode, so the suite can test both without restarting brokers (split-entities is normally a CLI/env start-up option). **Files to consider:** - `…/QueryEntities/D011_02_exc.robot` - `libraries/robotframework-httpctrl/src/HttpCtrl/http_stub.py` - `requirements.txt` _Originated from !277 (closed in favour of this issue)._