Different Levels of Evidence
    L0 = No name (N0) only
    L1 = name(s) (N1 or Ns) only
   L2a = N1 or Ns + ingredient/ingredients (I/Is) only
   L2b = N1 or Ns + preparation method/preparation
                   methods (PM/PMs) only
   L3 = N1 or Ns + I or Is + PM or PMs
   L4 = Traditional (e.g. has passed Traditional Thai Food Test)
   L5 = Differentiated from others by Comparative Gastronomy