The options for the country of birth are rather not well thought-through for Czechs, I can select CZ rep or Czechoslovakia for me but only CZ rep for my parents in the online application form.
I decided to fill the online application form and thought it was considerably easier to use than the paper form until I stumbled upon "select country of birth" and the drop-down menu showed both Czech Republic and Czechoslovakia. I was born pre 1993 so technically the latter is correct but I've ...