about query

Hi all,
Does anyone know what is the following query mean:
select * from abc,def where abc.xx(+) = def.xx
i have no idea about the (+) symbol..what it represent?
Thank you in advance
Best regards,
Ocurnos
As I know that + Symbol to used to join string.
example below
SELECT top 10 Title_ID + Title As "Title_ID + Title", * FROM
[pubs].[dbo].[titles]
Regards,
Rajesh
"Daniel" wrote:

> Hi all,
> Does anyone know what is the following query mean:
> select * from abc,def where abc.xx(+) = def.xx
> i have no idea about the (+) symbol..what it represent?
> Thank you in advance
> Best regards,
> Ocurnos