Check out example codes for "comments in xml". It will help you in understanding the concepts better.

Code Example 1

<!--Your comment-->

Code Example 2

<!--

	This will work in HTML and XML!
 
-->

Code Example 3

<!-- This is a XML comment. -->

Code Example 4

<detail>
    <band height="20">
    <!--
      Hello,
         I am a multi-line XML comment
         <staticText>
            <reportElement x="180" y="0" width="200" height="20"/>
            <text><![CDATA[Hello World!]]></text>
          </staticText>
      -->
     </band>
</detail>

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