What is the DOCTYPE for HTML5?
If you’re using HTML5, you’ll need to use this DOCTYPE:
<!DOCTYPE html>
As you can see, it’s an easy one to remember, and much easier than the traditional way:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">