It seems CSS behaves differently with and without the DOCTYPE comment. The HTML for my blog looks like
<!DOCTYPE html>
<html lang="">
<head>
<meta charset="utf-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1" />
...
</head>
...
</html>And the page renders fine.
However, if I remove the !DOCTYPE comment from the header, something odd happens: the social network icons at the bottom of my page float up a little bit.
I really don't know what is happening.