Index: branches/fc15-dev/server/doc/upgrade-tips
===================================================================
--- branches/fc15-dev/server/doc/upgrade-tips	(revision 2016)
+++ branches/fc15-dev/server/doc/upgrade-tips	(revision 2018)
@@ -197,2 +197,6 @@
 hysterical raisins we still refer to our 32-bit builds as i386.
 [XXX: Maybe this should change]
+
+Until we decide that the performance impact is negligible, any new PHP
+extensions other than the few we’ve whitelisted should be disabled by
+emptying their .ini files in /etc/php.d.