Pointing the validator at this submission and filtering out obsolete elements/attributes and all warnings/info messages, I still got 221 errors: No DOCTYPE, an

Pointing the validator at this submission and filtering out obsolete elements/attributes and all warnings/info messages, I still got 221 errors: No DOCTYPE, an script element after closing the body, duplicate element ids, and invalid attributes (not obsolete, they must be be using them like data-*).