Contains

Hi,

i need more information about use of contains clause in Oracle text.

If i try to select all spa companies in a table i write these select:

select score(1), des from p06_enti_est_pres

where contains(des, '(s.p.a.)', 1) >0

order by score (1) desc;

but as i not attended i found this string "A.P.S.P. Fondazione San Nicolo'" and i don't fount string contanis spa without dot.

If i search string with no dot i don't found string with dot.

Anyone can describe me how contains work?

Thank you,

Mariano