diff --git a/stable/xdg-shell/xdg-shell.xml b/stable/xdg-shell/xdg-shell.xml
index fb7b8b4..39ecf8a 100644
--- a/stable/xdg-shell/xdg-shell.xml
+++ b/stable/xdg-shell/xdg-shell.xml
@@ -514,7 +514,10 @@
 	The window geometry of a surface is its "visible bounds" from the
 	user's perspective. Client-side decorations often have invisible
 	portions like drop-shadows which should be ignored for the
-	purposes of aligning, placing and constraining windows.
+	purposes of aligning, placing and constraining windows. Note that
+	in some situations, compositors may clip rendering to the window
+	geometry, so the client should avoid putting functional elements
+	outside of it.
 
 	The window geometry is double-buffered state, see wl_surface.commit.