Create shipments and optionally a tour. When a property definition with an external validator applies to shipments or loads, the request is limited to 40 shipments and behaves per row unless a tour is requested: each shipment is validated and created independently, rejected rows are reported in the response's failed list with their zero-based request index, and all other rows are created (partial success). With a tour creation strategy the request stays one all-or-nothing booking. Without an external validator the request is unchanged: all-or-nothing, no row limit. Set matchShipperAddresses to true to match each stop against the assigned shipper's saved address book. Saved-address references sent on a stop (shipperAddressId, shipperAddressContactId, shipperAddressLoadingPoint) are always checked against the assigned shipper: with matchShipperAddresses true a reference that does not belong to that shipper is rejected with 400, otherwise it is removed and the shipment is created without it. A shipperId that does not exist in the tenant, or a team or user of another shipper, rejects the whole request with 422 and the violation codes of the assignment. The request or its shipments may name the assignment with shipperLookup instead of ids: the shipper, shipper team or shipper user that holds a property value (see the shipperLookup field for the rules and outcomes). The shipments store the resolved ids; a lookup that names no active holder, or more than one, rejects the whole request with 422, and one that cannot be answered right now with 503.