Common Tern

Dark-green ring with a white three alpha-numeric code.

note 1 :  used codes are : 
letter "M" / letter / number.

note 2 : used codes are :
letter "Y" / number / number
number / letter "Y / number
number / number / letter "Y"

note 3 :

Light-green/lime ring with a black three alpha-numeric code : 
* letter "Y" / number / number.
* number / letter "Y / number.
* number / number / letter "Y".

note 1 :

White ring with a black three alpha-numeric code : 
* letter "Y" / number / number.
* number / letter "Y / number.
* number / number / letter "Y".

note 1 :

Red ring with a white three alpha-numeric code : 
* letter "Y" / number / number.
* number / letter "Y / number.
* number / number / letter "Y".

note 1 :

Orange ring with a black three alpha-numeric code : 
* letter "Y" / number / number.
* number / letter "Y / number.
* number / number / letter "Y".

note 1 :

Yellow ring with a black three alpha-numeric code : 
* letter "Y" / number / number.
* number / letter "Y / number.
* number / number / letter "Y".

note 1 : some codes have used as first letter : N, P, R, or M followed by a letter and a number. These projects have not been agreed with the coordinator and may overlap with other cr-projects. 

note 2 :

Black ring with a white three alpha-numeric code : 
* letter "Y" / number / number.
* number / letter "Y / number.
* number / number / letter "Y".

note 1 : see also : http://www.cr-birding.org/node/5798

note 2 :
 

Dark-blue ring with a white three alpha-numeric code :
* letter "Y" / number / number.
* number / letter "Y / number.
* number / number / letter "Y".

note 1 :

Light-blue ring with a white three alpha-numeric code : 
* letter "Y" / number / number.
* number / letter "Y / number.
* number / number / letter "Y".

note 1 :

Black ring with a white 3 numeric code (on left leg) and metal ring (on right leg).

note 1 : used codes are : *.00 -*.99 , where * is a number.

note 2 :