Clarify used value and computed value

source

@@ -119112,7 +119112,11 @@ details[open] > summary {
 
   <p>For <code>input</code> elements whose <code data-x="attr-input-type">type</code> attribute is
   in one of the above states, the <span>used value</span> of the <span>'line-height'</span> property
-  must be no smaller than the <span>used value</span> would be for 'line-height: normal'.</p>
+  must be a length value that is no smaller than what the <span>used value</span> would be for
+  'line-height: normal'.</p>
+
+  <p class="note">The <span>used value</span> will not be the actual keyword 'normal'. Also, this
+  rule does not affect the <span>computed value</span>.</p>
 
   <p>If these text controls provide a text selection, then, when the user changes the current
   selection, the user agent is expected to <span>queue an element task</span> on the <span>user