Vertical Typesetting Synthesis: clarify rule priority for EAW=H

Author: kojiishi

css3-writing-modes/Overview.html

@@ -3820,7 +3820,8 @@ <h2 class=no-num id=vertical-typesetting-details>Appendix C: Vertical
       <li>Currency Symbols (Sc), Math Symbols (Sm), and Modifier Symbols (Sk)
 
 
-      <li>East Asian Halfwidth (H) characters
+      <li>East Asian Halfwidth (H) characters. This rule wins over other
+       rules based on General Category or Script.
 
       <li><abbr
        title="U+00B2, U+00B3, U+00B9, U+2070, U+2074–U+2079">Superscripts</abbr>,

css3-writing-modes/Overview.src.html

@@ -2868,7 +2868,8 @@ <h2 id="vertical-typesetting-details" class="no-num">Appendix C:
             <a href="#script-orientations">horizontal-only scripts</a>.
           <li>connectors (Pc) other than those listed as <a href="#typeset-sideways"><i>Sideways</i></a>
           <li>Currency Symbols (Sc), Math Symbols (Sm), and Modifier Symbols (Sk)
-          <li>East Asian Halfwidth (H) characters
+          <li>East Asian Halfwidth (H) characters.
+              This rule wins over other rules based on General Category or Script.
           <li><abbr title="U+00B2, U+00B3, U+00B9, U+2070, U+2074–U+2079">Superscripts</abbr>,
               <abbr title="U+2080–U+2089">subscripts</abbr>,
               and <abbr title="U+00BC–U+00BE, U+2150–U+215F, U+2189">fractions</abbr>