clarify exception by emphasizing it

Author: fantasai

css3-writing-modes/Overview.html

@@ -1702,7 +1702,7 @@ <h4 id=vertical-typesetting><span class=secno>5.1.1. </span> Vertical
         rel=biblioentry>[UAX11]<!--{{!UAX11}}--></a> of fullwidth (F) or wide
         (W).
 
-       <li>All Other Symbols (So) characters outside the Latin-1
+       <li>All Other Symbols (So) characters <em>except</em> those in Latin-1
         (U+000–U+00FF), Box Drawing (U+2500–U+257F), and Block Elements
         (U+2580–U+259F) blocks.
 

css3-writing-modes/Overview.src.html

@@ -1235,7 +1235,7 @@ <h4 id="vertical-typesetting">
           <ul>
             <li>All characters with an East Asian Width property [[!UAX11]]
               of fullwidth (F) or wide (W).
-            <li>All Other Symbols (So) characters outside the
+            <li>All Other Symbols (So) characters <em>except</em> those in
               Latin-1 (U+000–U+00FF), Box Drawing (U+2500–U+257F),
               and Block Elements (U+2580–U+259F) blocks.
             <li>All characters that belong to the Other Number (No) category