When fetching rel=compression-dictionary links: - Use "compression-dictionary" as request destination. - Properly set request's mode, credentials, referrer and referrerpolicy. - Take into account crossorigin and referrer attributes form <link rel="compression-dictionary">.
Compression Dictionary Transport was shipped in Chromium 130. Recently Mozilla and Igalia worked on some implementation in Firefox and WebKit, quite a bunch of tests have been added and the spec has been updated. This intent to ship is to catch up with the latest changes.