Yeah exactly. I can't even really find what I am trying to say, but Doctypes had some other piece of data with it. Was it a link or string to a spec? Like XHTML vs HTML4. Randomly I am sure that if you omit it, then it is "html5".which is random, shouldn't they have forced a spec HTML5?

That choice basically says to me that the idea of partitioning, or whatever those doctypes were for, is now abandoned.