Markdown formatting help doesn't pop to a new tab, as it should.
The clickable, little "(?)" in the top-right corner of post text entry box* causes an overlay to appear stating:
This forum is powered by Markdown. For full documentation, click here
The problem is that clicking on "click here" takes you to another page, interrupting any composition in progress. That should definitely be set to pop to another tab.
* As an aside, that "(?)" isn't as prominent as it should be -- it would be better as an explicitly titled "Formatting Help" link or button.
I can confirm this, it makes posting for beginners uneasy.