Alternative to Cache-Control response header for CDNs and reverse proxies.

Fastly reads this header from responses. It is proprietary to Fastly.

This is a companion discussion topic for the original entry at

Worth mentioning that setting this header in vcl_fetch won’t have any effect. If you want to control caching in vcl_fetch, you need to set beresp.cacheable/beresp.ttl/etc instead.

Also worth mentioning that Fastly strips out this header from the response before sending to the end user, which is documented at Cache freshness and TTLs.