Common Tern

Yellow ring with a black 3 alpha-numeric code : letter M followed by 2 numbers (on left leg) and metal ring (on right leg) OR number, letter M, number.

note 1 : birds ringed in Strathclyde Region, Scotland.

note 2 : used codes are M01-M99.

note 3 : 

Dark-blue ring with a white three alpha code, starting letter 'L or H' (on one leg) and metal ring (on other leg). 

note 1 : this project started in Northeast Germany in 2012. Until 2016 it was carried through with yellow rings with first letter 'F'.

note 2 : codes with second letter U, V, X and Z were used in southern part of East Germany (near city of Leipzig) in the years 2017 and 2018.

note 3 : from 2016, blue rings with the first letter being “H” have been used. Hence: blue “H” has been used from 2016 to 2019.

note 4 : 

White ring with a black three alpa-numeric code, starting letter "H", followed by a dot "." a letter and a number.

note 1 : used letters and numbers are : A, E, F, H, J, L, N, P, R, S, T, V, X, Z and 0 till 9.

note 2 :

Orange ring with a black 3 alpha-numeric code : letter U followed by 2 numbers (on left leg) and metal ring (on right leg).

note 1 : birds ringed in Leicestershire, UK.

note 2 : birds ringed during 2019.

note 3 : only used U00 to U17.

note 4 :

Orange ring with a a black three alphanumeric code (two numerics and letter K that might be on positions: nKn, nnK, where "n" is a digit 0-9) (on left leg) and metal ring (on right leg).

note 1 : used codes are :
K01-K16  (stop using)
0K0- 9K9
00K-99K

note 2 :

Green ring with a white three alpha-numeric code, starting-letter 'I'.

note 1 :

Yellow ring with a black three alpha-numeric code.

note 1 : used codes are : L and two numbers (L00-L99, 00L-99L, 0L0-9L9)

note 2 : letter 'L' on first, second or third position. Other two digests are numbers.

note 3 : birds ringed in the Dutch inland.

note 4 : the codes 50L untill 99L are used bij VRS de Haar. 

note 5 : other used codes are 00L-49L, 0L0-9L9 and L00-L99.

note 6 :

Red ring with a three alpha-numeric code, starting letter "I".

note 1 : 

Yellow ring with a three alpha-numeric code, starting letter "I".

note 1 : used codes are : I00-I99, IAA-IZZ, IA0-IZ9, I0A-I9Z.

note 2 :

Red ring with a white three alpha code, starting letter "Y".

note 1 : used codes are YAA-YZZ.

note 2 :