hixie: Recommend that TAB be supported in tooltips. (whatwg r6121)

hixie: Recommend that TAB be supported in tooltips. (whatwg r6121)

http://dev.w3.org/cvsweb/html5/spec/Overview.html?r1=1.4922&r2=1.4923&f=h
http://html5.org/tools/web-apps-tracker?from=6120&to=6121

===================================================================
RCS file: /sources/public/html5/spec/Overview.html,v
retrieving revision 1.4922
retrieving revision 1.4923
diff -u -d -r1.4922 -r1.4923
--- Overview.html	7 May 2011 20:31:52 -0000	1.4922
+++ Overview.html	7 May 2011 20:39:24 -0000	1.4923
@@ -65971,7 +65971,11 @@
   tooltip.</p>
 
   <p>U+000A LINE FEED (LF) characters are expected to cause line
-  breaks in the tooltip.</p>
+  breaks in the tooltip, U+0009 CHARACTER TABULATION (tab) characters
+  are expected to render as a non-zero horizontal shift that lines up
+  the next glpyh with the next tab stop, with tab stops occurring at
+  points that are multiples of 8 times the width of a U+0020 SPACE
+  character.</p>
 
   <p>User agents are encouraged to make it possible to view tooltips
   without the use of a pointing device, since not all users are able