HUB: POST /api/core/alert when anything is unclear or blocked, with the instruction not to guess, improvise or stall in a loop, then pause the task and keep heartbeating. SHAREPOINT: an Issue with a status, plus an Alert to whoever must answer. STATUS: the Issues list is HAVE; alerts are SPF.9. The valuable part is not the transport but the RULE, and it is one this platform needs as much as the hub does: a blocked agent that guesses is worse than a blocked agent that waits. Pair it with the Waiting on someone else state that ContentType.Task already declares - the vocabulary is there, the obligation to use it is not.