I certainly agree with not recommending inline CSS and restricting HTML usage to a few recommended tags. However I think there is a case for including <tt> in the list of recommended tags for the reasons I gave. It's no more complex than any of the other recommended tags, and allows you to do something you cannot achieve with out it. Alternatively, we could add a template, say Template:id, that simply does <tt>{{{1}}}</tt> for handling document identifiers, class marks, and such like. Then that becomes are accepted use, and direct use of <tt> remains not recommended. (And if it's too difficult to get base.css fixed, the template could be made to use inline CSS.)