Define base appearance for <select>

source

@@ -3864,7 +3864,12 @@ a.setAttribute('href', 'https://example.com/'); // change the content attribute
     <ref>CSSFORMS</ref></p>
 
     <ul class="brief">
-     <li>The <dfn data-x-href="https://drafts.csswg.org/css-forms/#picker-pseudo-element">picker
+     <li>The <dfn data-x-href="https://drafts.csswg.org/css-forms/#the-picker-pseudo-element">picker
+     pseudo-element</dfn></li>
+     <li>The <dfn data-x-href="https://drafts.csswg.org/css-forms/#selectordef-checkmark">checkmark
+     pseudo-element</dfn></li>
+     <li>The <dfn
+     data-x-href="https://drafts.csswg.org/css-forms/#picker-opener-icon-the-picker-icon-pseudo-element">picker-icon
      pseudo-element</dfn></li>
     </ul>
 
@@ -138165,6 +138170,17 @@ progress { appearance: auto; }</code></pre>
   <p>The <span>select popover</span>'s <span>implicit anchor element</span> is its associated
   <code>select</code> element.</p>
 
+  <p>When a <code>select</code> element is being rendered with <span>native appearance</span> or
+  <span>primitive appearance</span>, the <span>picker pseudo-element</span> and the
+  <span>picker-icon pseudo-element</span> do not apply.</p>
+
+  <p>The <span>picker pseudo-element</span> is not rendered when if it has <span>native
+  appearance</span> or <span>primitive appearance</span>.</p>
+
+  <p>The <span>checkmark pseudo-element</span> only applies to <code>option</code> elements which
+  are inside a <code>select</code> element whose <span>picker pseudo-element</span> has <span>base
+  appearance</span>.</p>
+
   <p>An <code>optgroup</code> element is expected to be rendered by displaying the element's <code
   data-x="attr-optgroup-label">label</code> attribute.</p>