routing from page to page through the database was arranged by the use of numbered items on index pages, which used the space in the frame routing table to map the index links directly to other page numbers. thus an index on page 747 might have links requiring the user to key 1 for "uk flights", key 2 for "flights to europe", or key 3 for "hotels" which represented links to page 74781, 74782, and 74791 respectively. the routing table for a particular frame only allowed specification of routes for digits 0–9, so double digit routes would typically be sent via an "intermediate" frame, usually a spare frame elsewhere in the ip's database, to which the first digit of all similarly numbered items would link. since pressing a number would interrupt a page that was currently being displayed, the keying of a double digit route would not generally inconvenience the viewer with the display of the intermediate frame.