§8.2.

Forward Handling

Relays SHOULD set the Forward flag to 1 when a new subscription needs to be sent upstream, regardless of the value of the Forward field from the downstream subscription. Subscriptions that are not forwarded consume resources from the publisher, so a publisher might deprioritize, reject, or close those subscriptions to ensure other subscriptions can be delivered.

This is one section of the MoQT specification, rendered per-section for quick reference and citation. The authoritative text is draft-ietf-moq-transport-15 at the IETF.