Falcons

Combination of :
* yellow ring with a black three alpha-numeric code (on one leg).
* metal and one (red) c-ring (on other leg). 

OR

* white ring with a black three alpha-numeric code (on one leg).
* metal and one (red) c-ring (on other leg).

note 1 :
first letter can be P, R, S, T, V, W, X, Y or Z.
second is a letter.
third is letter 'W'.

note 2 :
for the yellow set usde codes are : 11W–0ZW and A1W–J0W.
for the white set used codes are : 11W–0ZW and A1W–Z0W.

note 3 :