Pour créer un 'alias' dans firefox, pratique !
For example, the link http://www.youtube.com/watch?v=HXi-8nLK_dc
Bookmark the page and edit it.
Edit the link so you keep the "http://www.youtube.com/watch?v=" chunk, but replace the video ID with "%s" so it becomes "http://www.youtube.com/watch?v=%s"
Give the bookmark a keyword such as "yt"
Test by typing "yt HXi-8nE65JshkU" into the Firefox address bar.