```
<style type="text/css">
<!--
.style1 {
    color: #666666;
    font-weight: bold;
}
.style8 {font-size: 12px; color: #333333; }
.style9 {
    font-size: 12px;
    font-weight: bold;
    color: #FFFFFF;
}
.style12 {font-size: 12px; font-weight: bold; color: #666666; }
.style13 {font-size: 12px; font-weight: bold; color: #0066FF; }
.style14 {
    color: #0043A8;
    font-size: 16px;
}
.style15 {color: #FFFFFF}
.style16 {color: #990000}
.style18 {color: #990000; font-size: 12px; }
.style20 {font-size: 12px; font-weight: bold; color: #575757; }
-->
</style>

```

above stylesheet is enclosed in `<!-- -->` html comments tag. why? I can't get valid explanation for this; some tutorials do this while some doesn't (like <http://www.w3schools.com/css/css_howto.asp> which I think is very valid reference)
['https://Stackoverflow.com/questions/14749629', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/1684670/']
that's not a comment... it's a way to hide such text block from old browsers parser (mainly IE6-)

It's the same as using the [CDATA](http://en.wikipedia.org/wiki/CDATA) technique on the `<script>` tag... to **protect bad parsing of the data** from really weird engines (mainly IE) :)

though the **correct way** would be using:

for styles
==========

```
<style type="text/css">
/*<![CDATA[*/
    body { color: yellow; }     
/*]]>*/
</style>

```

for scripts
===========

```
<script type="text/javascript">
//<![CDATA[
    $(function() { ... });
//]]>
</script>

```

using `CDATA` in both cases is the **correct and safe way**, the *comment* way it's just a trick to accomplish the same end result.

---

Now, regarding your **I think is very valid reference** when pointing out W3Schools, have a look at this: 

> 
> <http://w3fools.com/>
> 
> 
>
It's a hack for older browsers that didn't support CSS/style tag... See <http://www.w3.org/TR/html4/present/styles.html#h-14.5>