# Shepherd Writeup for draft-ietf-httpbis-immutable
## 1. Summary
Mark Nottingham is the document shepherd; Alexey Melnikov is the responsible Area Director.
The immutable HTTP response Cache-Control extension allows servers to identify resources that will
not be updated during their freshness lifetime. This assures that a client never needs to
revalidate a cached fresh resource to be certain it has not been modified.
The requested publication type is Proposed Standard.
## 2. Review and Consensus
This document quickly gained broad interest within the Working Group, and then support. It has been
reviewed by a substantial number of participants, and implemented by Mozilla in Firefox, and by
Facebook and others on the server side. Microsoft and Squid have stated that they are in the
process of implementing.
## 3. Intellectual Property
The author has stated that their direct, personal knowledge of any IPR related to this document
has already been disclosed, in conformance with BCPs 78 and 79.
## 4. Other Points
No other points.