From 4cfbeba2412caceb5e12e32c1ed61dde884f4d35 Mon Sep 17 00:00:00 2001
From: Martin Thomson <martin.thomson@gmail.com>
Date: Thu, 30 Jun 2016 11:10:43 +1000
Subject: [PATCH] Provide rules for handling duplicate keys

---
 draft-ietf-httpbis-http2-encryption.md | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/draft-ietf-httpbis-http2-encryption.md b/draft-ietf-httpbis-http2-encryption.md
index 326e46779..53fb05141 100644
--- a/draft-ietf-httpbis-http2-encryption.md
+++ b/draft-ietf-httpbis-http2-encryption.md
@@ -171,6 +171,12 @@ Connection: close
 }
 ~~~
 
+The JSON format for the http-opportunistic resource makes it possible to include multiple values
+for the same origin.  Variations in case allow for duplicate keys that a JSON parser will treat
+as different.  Duplicated keys might not be detected by a client (see Section 4 of {{RFC7159}}).
+A client SHOULD NOT use origin objects if multiple keys match, though it MAY use any origin
+object with a matching key.
+
 Note that this mechanism is only defined to establish reasonable assurances for the purposes of this
 specification; it does not apply to other uses of alternative services unless they explicitly invoke
 it.