The birds in this project have multiple colour rings and a metal ring. All rings are on the lower legs. The metal ring is not part of the colour code.
The colour code consists of a sequence of the codes of the different rings. The codes of the rings on the left leg and those on the right leg are separated by a slash ("/"). A plain coloured ring consists only of the letter of the colour. A ring with an inscription consists of the letter of the colour followed by the letter of the inscription colour and the text on the ring in brackets.
Example RWN(A)/Y. This bird has plain red ring on top of a white colour ring with a black letter A on the left leg. On de right leg there is a plain yellow ring.