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.
clipped (shorter) wings increased the roll rate and airspeed at lower altitudes [aircraft from No.316(Polish) Squadron, August 1943]
Spitfire Mlk.Vb Trop
1) clipped (shorter) wings increased the roll rate and airspeed at lower altitudes.
2) fitted with the Aboukir air filter.
[aircraft from No.40 Squadron, South African Air Force, Tunisia, April 1943]