(long tweet) How to use comments in JSF 2?
If you write comments in an XHTML file (used by JSF2) as regular XML comments (ie starting with <!-- and ending with -->), you may probably find them in the HTML source generated “by” JSF. To prevent that, add the following bloxk in your web.xml:
[xml]<context-param>
<param-name>facelets.SKIP_COMMENTS</param-name>
<param-value>true</param-value>
</context-param>[/xml]