gl_ClipVertex not supported yet
diff --git a/docs/shading.html b/docs/shading.html
index 48ae15f..cb2c1c3 100644
--- a/docs/shading.html
+++ b/docs/shading.html
@@ -44,6 +44,7 @@
 <li>Linking of multiple shaders is not supported
 <li>Integer operations are not fully implemented (most are implemented
     as floating point).
+<li>gl_ClipVertex
 </ul>
 
 <p>