B-type wing - carry one 20 mm Hispano cannon (replaced the two inner .303 machine guns) + two .303 machine guns per wing
C-type wing - universal wing, can be eight .303" Browning machine guns, two 20 mm Hispano cannon + four .303 machine guns (most common) or four 20 mm Hispano cannon
Trop. (Tropical) - air filter (Aboukir filter or Vokes filter) fitted under the nose, in action in the North Africa.