You can add comments in HTML using this code.

HTML comment tag

<!-- Write your comments here -->

Add a Comment in your HTML code

<!-- This is a comment -->

<p>This is a paragraph.</p>

<!-- Remember to add more information here -->

Hide Content

you can hide content you using this code

<p>This is a paragraph.</p>

<!-- <p>This is another paragraph </p> -->

<p>This is a paragraph too.</p>

you can hide more than one line between <– here is your text –>

<p>This is a paragraph.</p>
<!--
<p>Look at this cool image:</p>
<img border="0" src="pic_trulli.jpg" alt="Trulli">
-->
<p>This is a paragraph too.</p>

Hide Inline Content

You can hide inline content using this code

<p>This <!-- great text --> is a paragraph.</p>