One:<link rel="shortcut
icon
" href="favicon.ico" />
Two:<link rel="icon" href="animated_favicon.gif" type="image/gif" />
When you need a icon for a web page ,the first line must exist, most browsers can identify the "icon" while the "shorticon" will be ignored, and IE can identify "shortcut icon" as one single name.
The second line just a backup for the new broswers in the furture.