> When I use a left join or outer right join a must use the joinLinks
> property?

Not if you use the "new" join syntax.
LEFT OUTER JOIN TABLEX ON ....

JoinLinks are only necessary if you try to use the "old" syntax
SELECT ... FROM TABLEX, TABLEY
WHERE ...

Or to quote the IBO ONLINE HELP

"If you are using a version of IB 5.x or higher, you are strongly
recommended to use explicit JOIN syntax and take special care to avoid
mixing the two syntaxes in one statement, which can cause server-side
ambiguities that IBO can not detect or control. You do not need
JoinLinks for a statement that uses pure explicit JOIN syntax."

--
Geoff Worboys
Telesis Computing