Similar to html, place everthing in a <\!– –\>. Example:
<\!– this is a comment –\>
p/s: please remove “\” – the example dont come out if I dont put \ in between
Reference:
http://webdesign.about.com/cs/xmlinformation/ht/htcommentxml.htm
http://www.hwg.org/resources/faqs/xmlFAQ.html