The warbook is a database of known friendly and enemy ships in the Colonial fleet database. The warbook is accessed through the scanner equipped on most Colonial ships.
Apollo scans the warbook from his Viper cockpit to confirm the configuration of two mysterious Cylon tanker craft found hidden within a gas cloud not from from the anticipated battlestar rendezvous point with the Cylons for the expected peace treaty signing.
Apollo soon discovers the tankers were used to refuel a massive group of Cylon Raiders large enough to destroy all the battlestars massed near Cimtar (TOS: "Saga of a Star World").