Abstract This specification defines a HTTP/2 frame type to allow clients to inform the server of their cache's contents. Servers can then use this to inform their choices of what to push to clients. Note to Readers The issues list for this draft can be found at https://github.com/mnot/I-D/labels/h2-cache-digest . The most recent (often, unpublished) draft is at https://mnot.github.io/I-D/h2-cache-