I was reading this blog by  James Bennett regarding HTML vs XHTML . He writes :I dont have any need for namespaced content; Im not displaying any  complex mathematical notation here and dont plan to, and I dont use  SVG for any images. So thats one advantage of XHTML out the window. I  also dont have any need for XML tools; all the processing I need to  do can be handled by HTML-parsing libraries like BeautifulSoup. Thats  the other advantage gone.What does he mean by namespaced content and what advantage does it provide us ?
What is meant by namespaced content and what advantages does it have?
html;html5;namespace;xhtml
XML namespaces allow including XML elements defined in a schema other than that of the main document. Specifically, the article talks about MathML and SVG, which are XML-based formats that can be directly embedded in an XHTML document using namespaces, looking like this:<html xmlns=http://www.w3.org/1999/xhtml      xmlns:m=http://www.w3.org/1998/Math/MathML>  XHTML content goes here  <m:math>      MathML content goes here  </m:math>  more XHTML content</html>