diff -r bf6b476f3b36 -r 80c5b2666a96 contrib/synthrepo.py
--- a/contrib/synthrepo.py	Fri Apr 10 23:12:33 2015 -0700
+++ b/contrib/synthrepo.py	Tue Apr 28 16:44:37 2015 -0400
@@ -41,6 +41,10 @@
 from mercurial.i18n import _
 from mercurial.node import nullrev, nullid, short
 
+# Note for extension authors: ONLY specify testedwith = 'internal' for
+# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
+# be specifying the version(s) of Mercurial they are tested with, or
+# leave the attribute unspecified.
 testedwith = 'internal'
 
 cmdtable = {}