anchor.diff:      property EventDate: TDateTime read FEventDate write FEventDate;
       property DatumKey: string read FDatumKey write FDatumKey;
       property EventType : TmUprightEventType read FEventType write FEventType;
  +    property Reference : TObject read FReference write FReference;
  +    property OwnsReference : boolean read FOwnsReference write FOwnsReference;
     end;
   
     { TmUprightDatum }
  
positive.code:     FAttributes[i].Free;
      FValues[i].Free;
    end;
    inherited Destroy;
  end;
  
  
negative.code:   EventDate:= 0;
    DatumKey:= '';
    EventType:= etuValue;
    FReference := nil;
    FOwnsReference:= false;
  
    for i := 0 to MAX_NUM_OF_ATTRIBUTES -1 do
    begin
  