Extension of Signed Exchanges that prefetches critical sub-resources (CSS, JS, images, fonts) together with the main HTML. The origin or a proxy emits a Link HTTP header listing each sub-resource URL along with an integrity (SHA) hash. Constraints: sub-resources must use long Cache-Control (1 year ideal), no cookies, no HSTS, must share the main document's domain, and there must be at most ~20 of them (excess ones are ignored). All-or-nothing: if even one sub-resource fails to prefetch, the browser discards every prefetched resource (privacy guarantee). Leads to a trade-off between completeness (prefetch everything) and reliability (small error rate).