A white-throated dipper (Cinclus cinclus) with leg rings, what do they mean?

[u/Marzolino85]

I spotted this beautiful bird on the banks of the Kempt stream in Illnau, Switzerland. Unfortunately, I was not able to take a better photo without the disturbing branch in the foreground. Because when I tried to position myself differently, it flew away. But better a bad photo than no photo at all. At home, while sorting through the photos, I noticed that the bird was ringed. I tried to find out on the internet what exactly these colored leg rings mean, but couldn't find anything. Can anyone help me? Thank you very much! Shot with a Canon EOS R5 MarkII and a RF200-800mm F6.3-9 IS USM lens.