A race car log book is a document certifying that a car is prepared to a given set of rules and is safe for competition (usually concerned with roll cage

Roll cage

A roll cage is a specially constructed frame built in the cab of a vehicle to protect its occupants from being injured in an accident, particularly in the event of a roll-over. Roll cages are used in nearly all purpose-built racecars, and in most cars modified for racing...

 construction). Log books are usually issued by a certified technical inspector for a motorsports

Auto racing

Auto racing is a motorsport involving the racing of cars for competition. It is one of the world's most watched televised sports.-The beginning of racing:...

sanctioning body. All competitions entered as well as the condition of the car before and after each competition must be entered in this book. Using log books is required by most sanctioning bodies for most upper levels of motorsports.