Summary
Vary support is now available in Cache Rules on every plan. You can normalize known negotiation headers, pass exact values through to the origin when those small differences matter, or bypass cache when the variation is too unpredictable.
Why it matters
Infrastructure and web-protocol changes can affect performance, caching behavior, reliability, and how applications are delivered to users. Developers and website operators should understand changes that could influence hosting architecture or production behavior.
Source
Cloudflare Blog ↗