2.1.50 [CSS-Level2-2009] Section 9.6.1, Fixed positioning


The specification states:

 Fixed positioning is a subcategory of absolute positioning. The only difference is 
 that for a fixed positioned box, the containing block is established by the 
 viewport. For continuous media, fixed boxes do not move when the document is 
 scrolled. In this respect, they are similar to fixed background images. For paged 
 media, boxes with fixed positions are repeated on every page. This is useful for 
 placing, for instance, a signature at the bottom of each page. Boxes with fixed 
 position that are larger than the page area are clipped. Parts of the fixed 
 position box that are not visible in the initial containing block will not print.

Quirks Mode (All Versions)

The fixed value of the position property is not supported.