HTML is definitely not allowed in page titles nor in url path segments. But there is no reason why it should not be allowed in the display string of a navigation item. Therefore I added a "escapeXmlInNavTitle" flag to the SimpleNavigationTag (default set to "true" which complies with the behavior so far. The way it works:

• When "escapeXmlinNavTitle" is set to false
• and the display string was read from the "navTitle" field (not from the "title" or "name")
• and it contains HTML

the HTML is not escaped and therefore displayed as intended. This will allow for stuff like partially colored or bold nav item text etc. like "why <b>simple</b> is <b>beautiful</b>"