Cloudflare, Inc. Akamai Technologies, Inc. This document specifies new HTTP/2 frame types and new HTTP/2 settings values that enable the use of previously transferred data as compression dictionaries, significantly improving overall compression ratio for a given connection. In addition, this document proposes to define a set of industry standard, static, dictionaries to be used with any Lempel-Ziv based compression for the common textual MIME types prevalent on the web.