--- a/master/painting.html	Sat Aug 18 17:42:24 2012 +1000
+++ b/master/painting.html	Sat Aug 18 17:51:26 2012 +1000
@@ -2205,6 +2205,10 @@
 <span class="property">'marker-knockout-left'</span> and
 <span class="property">'marker-knockout-right'</span> properties</h3>
 
+<p class="issue">The marker knockout properties are still under heavy development
+and are subject to change. Feedback on how authors might prefer to specify marker
+knockout shapes is welcome.</p>
+
 <table class="propdef">
   <tr>
     <th>Name:</th>