If you click the links above it’ll look like they go to the same page, but I assure you they’re different.Click the More Options link to see on each page to see.
I’ve included some screenshots at the bottom of this post to show the full code I used to check under each doctype.
You can click any of the 3 images for a larger and readable image.
Sometimes when you run a page through a validator the list of errors seems so large that it looks like it will take days to fix them.
Often a few simple errors are leading to many more.
Note that I also left off the period after “This is a sentence” above, which violates the rules of grammar, but likely doesn’t cause any problems in communication.