Differences with HTML 4
March 25th, 2010
This section is informative. Due to the fact that XHTML is an XML application, certain practices that were perfectly legal in SGML-based HTML 4 [HTML4] must be changed. 4.1. Documents must be well-formed Well-formedness is a new concept introduced by [XML]. Essentially this means that all elements must either have closing tags or be written in [...]