I have reviewed this document as part of the security directorate's ongoing effort to review all IETF documents being processed by the IESG. These comments were written primarily for the benefit of the security area directors. Document editors and WG chairs should treat these comments just like any other last call comments. Summary: Has minor issues. This draft defines a status code for sending an informational response that contains header fields that are likely to be included in the final response. A server can send the informational response containing some of the header fields to help the client start making preparations for processing the final response, and then run time-consuming operations to generate the final response. The informational response can also be used by an origin server to trigger HTTP/2 server push at a caching intermediary. Passed nit checker without complaints other than publication date. Sections 5 and 6 should be appendices. One minor issue: in the security considerations section, "Therefore, a server might refrain from sending Early Hints over HTTP/1.1 unless when the client is known to handle informational responses correctly" is a bit squishy (and contains a superfluous "when"). I'm not sure this merits a text change and I'm rather certain that it doesn't merit normative 2119 language but it did stand out as an overly soft recommendation.