select 
   iif( cast('ÑŃ' as varchar(10) character set utf8) collate unicode_ci_ai 
        containing 
        cast('nn' as varchar(10) character set utf8) collate unicode_ci_ai, 1, 0) 
from rdb$database;
select 
    iif( cast('ß' as varchar(10) character set utf8) collate unicode_ci_ai 
         containing 
         cast('ss' as varchar(10) character set utf8) collate unicode_ci_ai, 1, 0) 
from rdb$database;