Rent Period

Hi!
I'd like to ask about rent period in client.
So, in my db i cant set rent period for items because there's no row for it in Item table.
Do i need to set it somewhere else?
And how is it work? Do i need to only configure it in the database or i need to set it in the zitem too? I have seen some lines in zitem where rentperiod exists but i know how it works so :D please help me!

there's a tutorial on that in the TuT section. =D

I know how to use th search button :) but i cant find anything about it. Only for quest items, but i need this function for normal items. If you find one somehow please give me a link :D.