Somewhat simpler:

Code:
Sub M_snb()
   sn = [index(proper(B3:B12),)]
   
   For j = 1 To UBound(sn)
     If InStr(sn(j, 1), " ") Then
        If InStr(Split(sn(j, 1))(1), "/") = 0 Then sn(j, 1) = Replace(sn(j, 1), Split(sn(j, 1))(1), LCase(Split(sn(j, 1))(1)))
     End If
   Next
   [I3:I12] = sn
End Sub