When I view topics that have <pre> or spaced-indent text, in the Board-page, there are some formatting oddities - a very large (hundreds of pixels) indent.
E.g. at http://flow-tests.wmflabs.org/wiki/Testwiki:Support_desk
go to the topic "A lot of system pages don't have "nofollow, noindex" tags" and look at the 2 posts by User:126.96.36.199 and User:Fokebox
Ditto for the post by User:188.8.131.52, in the topic open_basedir to folder i did not found...
However, it looks fine/expected when seen in the Topic-pages themselves: