Terns

Combination of orange ring over dark-blue ring (on left leg) and metal ring over white ring with code (3 black letters). (1)

Combination of green over red ring (on left leg) and metal ring over white ring with code (3 black letters). (2)

Combination of a white ring with black 3 alpha code (starting letter 'B' or 'C') and white ring over metal ring (on right leg). (3)

note 1 : white ring with black code (3 black letters) is to be read vertical is on the tarsus and used letters are A, B, C, E, H, I, K, L, N, O, P, S, T, V, X, Z. 
note 2 : birds ringed in France, (SE France , dept. Hérault near Montpellier).
note 3 : (2) : 171 birds ringed in 2010 on 2 colonies, 1st letter is A or B.
note 4 : (3) on the 4th. of  July 2011, some 207 birds have been ringed at Marseillan, Southern France (near Montpellier).