When :hover Only Worked On Links

Internet Explorer 6 applied :hover only to anchor elements, so a rule like li:hover did nothing and pure-CSS dropdown menus were impossible there.

In 2026: Partly, by era. Both the list item and the link below highlight on hover in any current browser. In IE6 only the link would have reacted, because that browser limited :hover and :active to <a>. Authors bolted the behaviour onto other elements with Peter Nederlof's csshover.htc, a scripted behavior file.

Where it came from: The IE6 :hover limitation documented on Peter-Paul Koch's quirksmode.org. Worked around by Peter Nederlof's csshover.htc, around 2004. MDN ↗

<style>
/* In IE6 this list-item rule did nothing. :hover worked only on <a>. */
li.menu:hover { background: #fe9; }
a.old:hover  { background: #fe9; }  /* the only :hover IE6 obeyed */
</style>

<ul>
  <li class="menu">Hover this list item. Dead in IE6, works now.</li>
</ul>
<p><a class="old" href="#">Hover this link. Worked even in IE6.</a></p>