There's nothing visible. Is that the only way to tell if it's Czech?
Hi Adi , no you can tell it`s czech by it`s features , the very distinctive double rivets on the muzzle ring . The markings must have worn away , or perhaps it wasn`t stamped ! , but the blade ricasso should be marked CSZ ( which stands for Ceskoslovenska Statni Zbrojovky - czech state manufacture ) , usually these bayonets were also marked on the scabbard stud , again with CSZ and the czech lion and a number which represents the year of manufacture , hope that helps a little