Board Thread:Support Requests - Getting Technical/@comment-4193424-20170506162529/@comment-26402117-20170506164957

Looking at the date of the MediaWiki page creation (2014), I can guess this worked at a time where you could use the tag to add any arbitrary HTML to the page.

That won't work now for security reasons, so you will have to port it to a local script that passes JS review. Or you could enable article comments in Special:WikiFeatures.