Terns

species: 
Common Tern
scientific name: 
Sterna hirundo
notes: 

Black ring with a white three alpha-numeric code.

note 1 : used codes are :
letter 'T' - number - number  OR  number - letter 'T' - number  OR  number - number - letter 'T'.

note 2 : or another used code is : letter "M" / letter / number.

note 3 :

website sighting submit: 
Ornithological Station, Museum and Institute of Zoology of the Polish Academy of Sciences.
email sighting submit: 
colour-ring type: 
Legring : one, coded.
colour-ring colour (of the c-ring): 
Black (Niger) [N]
colour-ring code (of the c-ring): 
Three alpha-numeric code (3 letters/numbers).
countries where ringed: 
Poland.