Here are some illustrations of records from registry:
May it imply that the native Milcaks - "Taciturns" came from Poland?
Another variation of the surname is Milchak. I found it when I was searching for descendants of emigrants to the USA. Primarily I thought that this is different, only similarly sounding, surname. But finally it proved that most of the Milchaks have their ancestors in Slovakia and I also succeeded to find some links to Milcak family from Brutovce (see Milcaks from Brutovce).
I was thinking how this surname change could happened - quite simply, because of the sound of consonant "č". This sound was in the past written by means of ligatures cs, cz or ts. In English we can found this sound for example in words which or also witch. Thus the form Milchak is a variation which originates from the need to write somehow the sound "č".
In case of any difficulty with displaying the characters download this explanatory picture.
I am sorry to all linguist and phoneticists to whom my amateur explanation probably caused increase in heart rate and I welcome all comments and corrections.