Lesser Black-backed Gull

Yellow ring with a black unknown alpha-numeric code, starting letter 'S'.

note 1 : different colours are used each year and are yellow, orange, brown and black.

Yellow ring with a black four alpha-numeric code, starting letter 'H'.

note 1 : Hxxx, where xxx stands for numbers and letters.
note 2 : examples  are H99X, H123, HA67, HX43, H789, H23A.
note 3 : rings are to be read from bottom to top, most rings have a “checkpoint”.
note 4 : birds are ringed at Amrum (SH) (700) and at Helgoland (SH) (600) and at other places in Schleswig- Holstein.
note 6 : some rings are used at Herring Gulls, see this species.

Yellow ring with a 2 alpha-numeric code code

note 1 : rings are placed above the knee (on the tibia) for better observation results in the colony (high vegetation) and on rubbish-dumps. All other colours (with vertical placed codes) above the knee are also part of this project.

note 2 : In some series  used dots (1.A), colons (1:A) or single or double bars (1|A or 1||A). Those additional marks are part of the code

note 3 : In some series is an additional plain marker present at the other tibia, this marker is part of the combination.

note 4: Same codes can be used by other large gull species. If you have doubts about the species and/or code, please note the age and position of all the rings, including the metal ring.

note 5: used letters/numers are : A, B, C, D, E, F, G, H, J, K, L, M, N, P, R, S, T, U, V, W, X, Y, Z, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, + and =. Only the letters I, O and Q are never used

note 6: In this project are also used a combination of two coloured rings with both one letter or number at each tibia.

Yellow ring with a black three alpha code, starting letter 'A'.

note 1 : some 20birds are ringed in the framework of a wildlife rehabilitation centre near Hastings, East Sussex.

note 2: during 2000 yellow was used, other colours in other years.

Combination of :
* a white ring (on left leg) with black code (1 alpha-numeric code or 1,2 or 3 horizontal bars) and green ring (on right leg) with white code (1 alpha-numeric code or 1,2 or 3 horizontal bars).
* a white ring (on left leg) with black code (1 alpha-numeric code or 1,2 or 3 horizontal bars) and red ring (on right leg) with white code (1 alpha-numeric code or 1,2 or 3 horizontal bars).

White ring with a red three alpha-numeric code, one number and two letters.

note 1 : used code on 22 birds in 1998 is: 1AS-2CS.

note 2: this project is running on the Scilly Islands, UK.

White ring with a black two alpha code.

note 1 : all rings are of the same design, with the letter repeated round the ring, so that the letters read horizontally on a standing bird. See image.

note 2 : birds are ringed as breeding adults on Skomer Island, Wales, as part of long-term population monitoring dating back to the 1970s

note 3 : Only the 20 letters A, B, C , D, F, H, I, J, K, L, N, O, P, S, T, U, V, X, Y, Z are used, since the others are too large (W , M) or too likely to other letters (E, G, Q, R).

note 4 :

White ring with a red three alpha-numeric code : one number and two letters.

note 1 : used codes are 1AH-9YH.

note 2 : 

White ring with a black three alpha-numeric code.

note 1 : starting letters are 'T' or 'BP' or S.

note 2 : 

White ring with a black four alpha-numeric code, starting letter 'C'.

note 1 : up to 2014, a total of 10286 rings were delivered since 1993-...

note 2 : there can exist small check marks in the code (like dots between characters), inform them also.

note 3 :