This gull was marked as 1st calendar-year male with a Dutch metal Arnhem ring 3555080 on December 30, 1995 in Decenter, the Netherlands (52°16'0.0''N, 6°10'0.0''E). On May 17, 2012 the white ring TRCR was added in the breeding area in north-east Poland (53°55'14.3''N,21°30'28.6''E ). The Katwijk sighting was the first reported after addition of the color ring. I saw it again in Katwijk on December 21, 2014.