enum System.Reflection.ParameterAttributes flags:

   def enum
      None = 0
      In = 1
      Out = 2
      Lcid = 4
      Retval = 8
      Optional = 16
      HasDefault = 4096
      HasFieldMarshal = 8192
      Reserved3 = 16384
      Reserved4 = 32768
      ReservedMask = 61440.

end enum.
