Re: Petko/Petke, Kovacik
It was Austria-Hungary http://users.erols.com/mwhite28/austhung.htmhttp://users.erols.com/mwhite28/austhung.htm in which empire 12 different languages spoken.Might you know the language of your ancestor? KOVAC^IK is a Slavic surname.
KO would suggest a Byzantine Catholic/Ruthenian, few exceptions, of course.
I find PET^KO and KOVAC^IK in Slovak Republic's phone book.