If you click it enough times, you can get anything on the table of
contents to spill over into the page text area. I'm not sure that you
could keep it all within the color background of the TOC without
eventually becoming unreadable.
Load any Forrest page (http://forrest.apache.org/index.html)
Click +a repeatedly
Watch menu item 'Documentation' grow into the page text area.
Is this a known problem, should I report this in Jira?