'Declaration

Public ReadOnly Property Format As String

public string Format { get; }

public: __property string* get_Format();

public:
property string^ Format {
   string^ get();
}

'Nk' - k numeric digits, fixed length
'NkC' - k numeric digits + check digit, fixed length
'N..k' - up to k numeric digits
'X..k' - up to k characters ISO646