udev rules files don't need execute permission.
diff --git a/docs/html/guide/developing/device.jd b/docs/html/guide/developing/device.jd
index 35c0a1a..c00f312 100644
--- a/docs/html/guide/developing/device.jd
+++ b/docs/html/guide/developing/device.jd
@@ -145,7 +145,7 @@
               <code>SUBSYSTEM=="usb_device", SYSFS{idVendor}=="0bb4", MODE="0666"</code></p>
           </li>
           <li>Now execute:<br/>
-              <code>chmod a+rx /etc/udev/rules.d/50-android.rules</code>
+              <code>chmod a+r /etc/udev/rules.d/50-android.rules</code>
           </li>
         </ol>