Combination of :
* white flag with a two alpha-numeric (two numbers or two letters or a combination) code (on right or left tibia)
* orange ring (on right or left tibia) and metal ring (on left or right tarsus).
note 1 : used letters are : A,C, E, F, H, J, K, L, M, N, P, R, S, T, U, V, W, X, Y, Z.
note 2 : used numbers are 1, 2, 3, 4, 5, 6, 7, 8, 9, 0.
note 3 : ringed birds are juvenile (chick) or adult.
note 4 : birds ringed in Prov. Gelderland, Overijssel, and Zuid-Holland, The Netherlands.
note 5 :