 It is not clear if the prefix can be added to letters that have partners in the bottom row of the table above to distinguish, say, dagesh hazak "kk" from dagesh kal "k", or "ww" from "û".When transcribing completely unpointed print texts, only the top row of braille letters is used.Apart from those written with and and thus obligatory in print, vowels are optional in braille just as they are in print.