[css-overflow-3] Fix links

Author: fantasai

css-overflow-3/Overview.bs

@@ -92,13 +92,12 @@ Types of overflow</h2>
 	some of the children, any of their descendants with
 	''transform-style: preserve-3d'' must also be examined.
 
-	There are three different types of overflow,
+	There are two different types of overflow,
 	which are used for different purposes by the UA:
 
 	<ul>
 		<li><a>ink overflow</a>
 		<li><a>scrollable overflow</a>
-		<li><a>border-box overflow</a>
 	</ul>
 
 <h3 id="ink">Ink overflow</h3>
@@ -169,7 +168,8 @@ Scrollable overflow</h3>
 			and that overflow is not already clipped
 			by the 'clip' property.
 
-			Note: The 'masking' properties do not affect the <a>scrollable overflow region</a>.
+			Note: The 'mask-*' properties [[!CSS-MASKING-1]]
+			do not affect the <a>scrollable overflow region</a>.
 
 			Issue: Need to evaluate compat of honoring or ignoring 'clip' and 'clip-path'.
 	</ul>