What is (+) in where clause

I'm porting some Oracle views to SQL Server. Not being a Oracle dba, I'm having a problem with the syntax in one of the views. In a view, I see this in one of the where clauses:

where x.field = y.field(+)

What does the (+) do? Is this some function?

Thanks Received on Fri Jul 25 2003 - 09:53:25 CDT