oznakować (Polish) comes from Polish znakować, from Polish znak, from Old Polish znak, from Proto-Slavic znakъ, from Proto-Slavic znati, from Proto-Balto-Slavic źnōˀtei, from Proto-Indo-European ǵnéh₃t, from Proto-Indo-European ǵneh₃- — to know.
oznakować (Polish): to mark, to flag, to stamp