Thread:Project:Support desk/Square brackets in page titles / links

I'm porting a lot of content from a commercial Wiki system to MediaWiki but have many pages with square brackets in the page titles. It's starting to look like MW can't cope with page names (and links) containing square brackets.

I've tried using entities (&amp;#91; and &amp;#93;) but that doesn't work. I can't find any documented means of escaping characters.

Are square brackets completely forbidden in page titles and links? How does one deal with external URLs which contain square brackets?