( Basically it is the name of the menu entry you want to boot and a 3 ) . . . . It will then boot in level 3 . . . then you can login as "root" ( not "su" ) and do "XFdrake" to set the correct driver for your graphics card, or any other troubleshooting operation you need to perform.
When you are ready you can either type "reboot" or log out as root with Ctrl+D, then log in as user and type "startx", . . . and it will magically continue booting from level 3 to level 5.
NOTE: Sure you can type "PCLos 1" too so it boots in "single user mode" giving you a root-prompt, so in case you forgot the root-password you can just type "passwd" and change it to one you can remember next time you need it.

Bruno
-- May 24 2005 ( Revised Dec 15 2005 ) --