You're viewing a post from a previous season, Smart Move.
It's just like highlighting, except it's more like a professional-looking box.
Since I couldn't find the setting to turn HTML validation off, when you go to "Compose" view to change up the tags, blogger will also delete the curved corners and scramble up the code. (That's just what it does...) So, you guys are gonna have to edit the tags first, then I go last.
Oh, I forgot to add, the curved corners only work on Firefox, Chrome, and Safari. It doesn't work on IE or Opera. That's because I used a quick CSS3-Compatible attribute and IE doesn't have support for that brand new stuff yet. IE9 will, though.