This is similar to the other questions around but, the solutions that I’ve seen involve other plugins and things. The closest I’ve found to the “right” fix is

// STOP WORDPRESS REMOVING TAGS
function tags_tinymce_fix( $init )
{
  // html elements being stripped
  $init['extended_valid_elements'] = 'div[*],article[*]';
  // don't remove line breaks
  $init['remove_linebreaks'] = false;
  // convert newline characters to BR
  $init['convert_newlines_to_brs'] = true;
  // don't remove redundant BR
  $init['remove_redundant_brs'] = false;
  // pass back to wordpress
  return $init;
}
add_filter('tiny_mce_before_init', 'tags_tinymce_fix');

However, that doesn’t include the Definition list markup, list heads, and I’m sure I’m forgetting some.

Is there a way to make WordPress leave my html alone? There’s no reason to sanitize valid code … We’re not all monkeys …