I don't know if this is by design or not, but Stack Exchange accepts basic HTML in almost every thing you can write. I found out that I had a < strike > tag in my "Bio" and that isn't properly displayed in the "hover popup".
Here's the text I have when I edit my profile:
I use Apple hardware and Mac OS X since the age of dawn but work doing <strike>C#.NET Windows Programming inside VMWare/Parallels</strike> Android development using Eclipse and the Android SDK.
And this is how it looks:
The Strike tag is ignored.
Of course it's not ignored in the profile page.
Shall I remove that or is this a bug (or a feature)?