White ring with a black three alpha-numeric code, starting letter 'C' or 'F' or 'H' or 'J'.
note 1 : used codes are :
* letter "C" or "F" or "H" or "J" followed ny number and letter.
* letter "C" or "F" or "H" or "J" followed by letter and number.
* letter "C" or "F" or "H" or "J" followed by letter and letter ... thus three alpha code (see project : http://www.cr-birding.org/node/5066
note 2 :