f79r - something written under water ???

[Rafal]

I think there could be some writing or something like that under blue paint in one part of You are not allowed to view links. Register or Login to view. folio.

I altered the picture with graphic editor changing stuff like hue, contrast etc. :
   

For me it seems a bit like letters " k o ń r "
"Koń" is "horse" in Polish but I wouldn't go that far 

Do you see something too or is it just some random noise for you?