From 67e88da62ec58a19479e979ed890f30aae9cb890 Mon Sep 17 00:00:00 2001
From: Jonathan Ellis <jbellis@apache.org>
Date: Mon, 2 Apr 2012 16:37:43 -0500
Subject: [PATCH] clarify backwards-compatibility policy (CASSANDRA-3951)

---
 interface/cassandra.thrift | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/interface/cassandra.thrift b/interface/cassandra.thrift
index c34c927678..f0332f6e9f 100644
--- a/interface/cassandra.thrift
+++ b/interface/cassandra.thrift
@@ -46,6 +46,15 @@ namespace rb CassandraThrift
 #           for every edit that doesn't result in a change to major/minor.
 #
 # See the Semantic Versioning Specification (SemVer) http://semver.org.
+#
+# Note that this backwards compatibility is from the perspective of the server,
+# not the client. Cassandra should always be able to talk to older client
+# software, but client software may not be able to talk to older Cassandra
+# instances.
+#
+# An effort should be made not to break forward-client-compatibility either
+# (e.g. one should avoid removing obsolete fields from the IDL), but no
+# guarantees in this respect are made by the Cassandra project.
 const string VERSION = "19.20.0"