docs/EXPERIMENTAL.md: add a mention of HTTPSRR as experimental

Closes #16017

diff --git a/docs/EXPERIMENTAL.md b/docs/EXPERIMENTAL.md
index a8eab659bca0ada8c1714370a1412f45d6704228..43fc0fdeed885dcf1d0bcc789fa9f86d6f0f596c 100644 (file)
--- a/docs/EXPERIMENTAL.md
+++ b/docs/EXPERIMENTAL.md
@@ -75,3 +75,16 @@ Graduation requirements:
 - the implementation is considered safe
 
 - feedback from users saying that session export works for their use cases
+
+## HTTPS RR
+
+HTTPS records support is a requirement for ECH but is provided as a
+stand-alone feature that is itself considered EXPERIMENTAL.
+
+Graduation requirements:
+
+- HTTPS records work for DoH, c-ares and the threaded resolver
+
+- HTTPS records can control ALPN and port number, at least
+
+- There are options to control HTTPS use