In Belgium, the use of languages is free.
But in administrative matters, and your minutes of general meetings and sometimes even of board meetings are administrative documents, the use of languages is defined by a law of 1963. If your company has its registered office in Flanders, the minutes must be drawn up in Dutch. In the Walloon Region it must be drawn up in French and in the Brussels-Capital Region it must be drawn up either in French or in Dutch. The only exception is the AISBLs, who may write their minutes in English if they wish.