What are CSS @ Blocks?

In the CSS Outline, Visual Studio has a folder tit开发者_StackOverflow中文版led, "@ Blocks" . What is it talking about?

From W3...

Media Types allow you to specify how documents will be presented in different media. The document can be displayed differently on the screen, on the paper, with an aural browser, etc.

http://www.w3schools.com/Css/css_mediatypes.asp

so, this will show up in the "@ Blocks" section

@media print   
{  
    p.test {font-family:times,serif;font-size:10px;}
} 

@ Blocks is where Visual Studio will outline any @ statements. THe @ provide ability to add apply a set of rules to a specific declaration. They are also used for @import which allows you to nest CSS files. They are also used to define media type, for example @media print can set styles for when the page is printed. Here is the W3C definition: http://www.w3.org/TR/CSS2/syndata.html#x6