Customizing nls_sort and nls_comp in Oracle There is different letters for 'KAF' (ک , ك) and 'YA' (ی , ي) in Persian with different unicode codes and same spell.

I am using these commands to set Persian sort and comparing in my project

ALTER SESSION SET nls_sort=persian;

ALTER SESSION SET nls_comp =linguistic; 


With setting nls_comp and nls_sort parameter I receieve these output

select first_name from customer 
where first_name like '%ك'; -- with result

select first_name from customer 
where first_name like '%ک';--with no result


How can receive same output for these queries? Can I customize nls_comp ?
I think the Oracle Locale Builder utility is the tool that you want. The documention on the 10.2 version (since you've tagged with oracle-10g) of this utility is here: http://docs.oracle.com/cd/B19306_01/server.102/b14225/ch13custlocale.htm