The Zombie: Improper element nesting
<p>That zombie is checking you <b>out</p>!</b>Always a Zombie? Yes, however, some browsers may interpret it the way it’s intended rather than the way it’s written, but you never know which browser might do it correctly or not
Severity: Varies
Why it’s a Zombie: Browsers are pretty good at interpreting what you intended, but they might get it wrong and, possibly worse, some might get it right and some might get it wrong, meaning you might check it in one browser and think it’s great all the while your visitors are getting a broken page.
Cure the Zombie by: Always close an element before you close its parent.
<p>That zombie is checking you <b>out</b>!</p>