Ideally, we can support the full wikitext syntax for freeform text snippets in the Judgment namespace. As a more fallback plan, we would also be okay with some more limited syntax such as the way edit summaries are parsed. These seem to be parsing [[local links]] and nothing else.
Local links should show up in "what links here" (via entries in the links table) and new external links should be run through SpamBlacklist and other hooks.