Nested lists such as:
: foo :: bar
have a bit of a styling problem. The HTML generated is:
<dl> <dd>foo <dl><dd>bar </dd></dl></dd></dl>
and with this DOM tree there's no way to highlight/box foo with a CSS style without also surrounding bar.
What we'd like is HTML structure more like:
<dl> <dd><div>foo</div> <dl><dd>bar </dd></dl></dd></dl>
<dl> <dd>foo </dd><dd> <dl><dd>bar </dd></dl></dd></dl>
The former we could probably convince the legacy parser and/or Parsoid to emit; basically creating an initial <div> for the item and closing it as soon as a nested list is encountered. The latter would probably require new wikitext syntax (or flag, which could be set on certain types of pages), since it's a non-backwards-compatible change to the list semantics.
No specific proposal yet; this task is initially for discussion.