What's a valid HTML5 document?

Question

I\'ve just been reading the HTML5 author spec. It states that the , and tags are optional

Answer 1

W3C HTML validator maintainer here. FYI with regard to the validator behavior, as of today, the validator now enforces the requirement in the HTML spec that the title element must contain at least one non-whitespace character -

http://validator.w3.org/nu/?doc=data%3Atext%2Fhtml%3Bcharset%3Dutf-8%2C%3C%2521doctype%2520html%3E%3Ctitle%3E%2520%2520%2520%3C%252Ftitle%3E