13 The HTML syntax13.1 Writing HTML documents13.1.1 The DOCTYPE13.1.2 Elements13.1.2.1 Start tags13.1.2.2 End tags13.1.2.3 Attributes13.1.2.4 Optional tags13.1.2.5 Restrictions on content models13.1.2.6 Restrictions on the contents of raw text and escapable raw text elements13.1.3 Text13.1.3.1 Newlines13.1.4 Character references13.1.5 CDATA sections13.1.6 Comments13 The HTML syntax This section on