(Dark)Green ring with a white three alpha-numeric code (on right tarsus) and metal ring (on other leg).
note 1 : used letters are A, B, C, D, E, F, G, H, I, K, L, M, N, O, P, R, S, T, U, V, W, X, Y and Z.
note 2 : used numbers : 01 till 99.
note 3 : most codes are starting letter 'C' / number / number.
note 4 : birds ringed since 1990.
note 5 : first 10 years there were wing-tags as well, white with dark-blue letter(s).
note 6 :