Bug 316716 [Mac] Hide Tab Key navigation section in Help. Patch by Stefan <stefan_h@hem.utfors.se> r=iann_bugzilla

extensions/help/resources/locale/en-US/cs_nav_prefs_advanced.xhtml

@@ -148,15 +148,16 @@
 </ol>
 
 <p>The Keyboard Navigation preferences panel allows you to control how you use
-  the keyboard to navigate and search for text in web pages:</p>
+  the keyboard to <span class="noMac">navigate and </span>search for text in
+  web pages:</p>
 
 <ul>
-  <li><strong>Links</strong>: If checked, pressing <kbd>Tab</kbd> or
-    <kbd>Shift</kbd>+<kbd>Tab</kbd> moves
-    between links.</li>
-  <li><strong>Buttons, radio buttons, check boxes, and lists</strong>: If
-    checked, pressing <kbd>Tab</kbd> or <kbd>Shift</kbd>+<kbd>Tab</kbd> moves
-    between buttons, radio buttons, check boxes, and lists.</li>
+  <li class="noMac"><strong>Links</strong>: If checked, pressing <kbd>Tab</kbd>
+    or <kbd>Shift</kbd>+<kbd>Tab</kbd> moves between links.</li>
+  <li class="noMac"><strong>Buttons, radio buttons, check boxes, and
+    lists</strong>: If checked, pressing <kbd>Tab</kbd> or
+    <kbd>Shift</kbd>+<kbd>Tab</kbd> moves between buttons, radio buttons, check
+    boxes, and lists.</li>
   <li><strong>Find automatically when typing within a web page</strong>: If
     checked, typing text in a web page automatically activates Find As You Type
     and locates the text you typed (if it exists in the page). Choose whether