dFdx(), etc. don't work yet
diff --git a/docs/shading.html b/docs/shading.html
index 3a10f1b..64ec999 100644
--- a/docs/shading.html
+++ b/docs/shading.html
@@ -44,6 +44,7 @@
 <li>Comparison of user-defined structs
 <li>Linking of multiple shaders is not supported
 <li>gl_ClipVertex
+<li>The derivative functions such as dFdx() are not implemented
 </ul>
 
 <p>