Does default XML namespace need a prefix?

Does default XML namespace need a prefix?

References

Reference NO 1

http://www.w3schools.com/xml/xml_namespaces.asp

Reference NO 2

http://www.w3.org/TR/REC-xml-names/

Reference NO 3

http://stackoverflow.com/questions/15188359/does-default-xml-namespace-need-a-prefix

Reference NO 4

http://en.wikipedia.org/wiki/XML_namespace

Reference NO 5

http://www.xmlmaster.org/en/article/d01/c10/

Reference NO 6

http://www.rpbourret.com/xml/NamespacesFAQ.htm

Reference NO 7

http://www.oracle.com/technetwork/articles/srivastava-namespaces-092580.html

Reference NO 8

http://msdn.microsoft.com/en-us/library/aa468565.aspx