6 Things should not do with HTML

<a href="#"><h2>Text</h2><a>

<h2><a href="#">Text<a></h2>

or

<a href="#"><h2>Wrong</h2><a>

<h2><a href="#">Right<a></h2>

or

Block Element

Inline Element

1. Don't put Block Element in Inline Element

<img src="image.jpg" alt="image">

2. Don't forget to put alt to img

<p>

    Monday<br/>

    Thuesday<br/>

</p>

<ul>

   <li>Monday</li>

   <li>Thuesday</li>

</ul>

or

<p>

    Monday<br/>

    Thuesday<br/>

</p>

<ul>

   <li>Monday</li>

   <li>Thuesday</li>

</ul>

or

3. ul/ol better than br

<b>Text<b>

<strong>Text<strong>

or

<b>This is bold<b>

<strong>So this is but Better!<strong>

or

4. strong/em better than b/i

Monday

<br/>

<br/>

Thuesday

<p>Monday</p>

<p>Thuesday</p>

or

Monday

<br/>

<br/>

Thuesday

<p>Monday</p>

<p>Thuesday</p>

or

5. Don't use multiple br

<h2 style="color:red"></h2>

6. Avoid Inline Style