Terns

species: 
Sandwich Tern
scientific name: 
Thalasseus sandvicensis
notes: 

Red ring with a white three alpha-numeric code, starting letter "S" or "U" followed by two numbers.

note 1 : used numbers / codes are : 0, 1, 3, 4, 7, 9 so as ex. : S01, S03, S04, S07, S09, S10, S11, S13, S17, S19 and so on.

note 2 : 

website sighting submit: 
Ringmärkningscentralen.
email sighting submit: 
colour-ring type: 
Legring : one, coded.
colour-ring colour (of the c-ring): 
Red [R]
colour-ring code (of the c-ring): 
Three alpha-numeric code (3 letters/numbers).
countries where ringed: 
Sweden.
First letter/number (of the c-ring): 
S or U