ZK generates the HTML code mostly on the client side, all the necessary information is inside a <script> tag. So is the HTML code created by the server is valid HTML.
But inspecting the HTML structure generated on the client side is not valid any more. I can see such things that
- <div> tags inside <span> tags (for example in Menu structure)
- <button href="...">
- <a disbaled="...">
Generating valid HTML code would improve accessibility of ZK webapps.