The different kinds of B were eventually written differently, so as to distinguish them in music theory treatises and in notation. The flat sign derives from a round "b" that signified the soft hexachord, "hexachordum molle", particularly the presence of B. The name of the flat sign in French is "bémol" from medieval French "bé mol", which in modern French is "bé mou" ("soft b"). The natural sign and the sharp sign derive from variations of a square "b" that signified the hard hexachord, "hexachordum durum", where the note in question is B. The name of the natural sign in French is "bécarre" from medieval French "bé quarre", which in modern French is "bé carré" ("square b"). In German music notation the letter "B" or "b" always designates B while the letter "H" or "h" – a deformation of a square "b" – designates B.