Oh I actually quoted the website's source. They have that DTD meta crap in there.
But I think you can just do <html> nowadays and it empirically just works. Seriously, screw the anti-DRY people that want me to put some !DOCTYPE or xmlns tags with some W3C links or some DTD nonsense inside ... I should only have to specify "html" exactly once, no more.
If I had designed the spec I would have just made it
<html version="4.0">
<html version="5.0">
<html version="5.1">
Incredibly more readable, and memorizable. A markup language (literally), by virtue of being a
markup language, should not be impossible to memorize. Making scary strings like "-//W3C///DTD" part of the spec is counterproductive.