Range request header can be passed through a service worker if it's not modified. This enables service workers can work with requests made by media elements such as video and audio.
This spec change means that range requests (such as those from media elements) are allowed to pass through a service worker as long as they aren't modified. This fixes a long standing issue where media elements behave oddly if intercepted by a service worker (as the range headers were lost).
Explainers: https://github.com/whatwg/fetch/pull/560