[otrs] sub-queue-ing

Hi all, i've noticed, that OTRS allows only 3 levels of sub-queues. Is there a reason why is that and is it possible to extend that to more than 3 levels. Example: 1. level: main_queue: 2. level: sub_queue 3. level: sub_queue best regards, P.S. we are still using OTRS 2.0 - is this issue relevant for version 2.1 too? --alexm