Albert de Jong
Larus cachinnans adult UKK L-002095 May 06 2013, Gatovo - Minsk, Belarus. Picture: Dmitry Goncharov.
Bird ringed UKK L-002095, ringed in Ukraine, now in the rooftop breeding colony in Minsk. Exact data pending, probably pullus 2003-2004, also note bad condition of ring. However, Armin Deutsch photographed a Kiev ring pretty close in code, ringed in 2007 at Lake Svityaz, Shatskiv Distr. Ukraine (51°28'00"N, 23°50'00"E). This is the most north eastern lake and probably visible from the border with Poland and Belarus (with telescope at least); see L-002197.
Below: roof top nesting in Belarus.
This is what local ornithologist Dmitry says: