TTntLVOwnerDataFindEvent = procedure (Sender: TObject; Find: TItemFind; const FindString: WideString; const FindPosition: TPoint; FindData: Pointer; StartIndex: Integer; Direction: TSearchDirection; Wrap: Boolean; var Index: Integer) of object;

TntComCtrls

This is type TntComCtrls.TTntLVOwnerDataFindEvent.