To find a File Number in the Federal Register Library, you can use the Advanced Search option at the top of the main page. You will need to use the Full Text field option from the drop down menu.
Example: “File No. SR-CBOE-2006-14”
You can also search using the one-box search bar at the top of the page. From here you would type “File No. SR-CBOE-2006-14” and select Just search for from the drop-down, then hit the search button.