Variable:flags

A number of flags for vehicles:

anytrack = Can it run on any type of track? (used by buses and trucks)
bit_0 = Unknown
bit_8 = Unknown
bit_B = Specifies if the vehicle can couple
dualhead = If the vehicle requires two locomotives (for example, the TGV)
noannounce = If the news announcement disabled when this vehicle is invented
rackrail = Can the vehicle use a rack rail?
refittable = If the vehicle is refittable(mostly planes and passenger boats) (Refitting allows only mail, food, goods, and grapes. New capacity is passenger capacity divided by 2.5)