I'm guessing that you are referring to the rules for posting a thread on the Rent/Trade board when a DVC member has points available to rent out or transfer to another DVC member. This rule means that you must either be an active member of the disboards with a recent posting history or else pay for a membership for that privilege.
Just a minder, you only need the rental plan IF you are offer your points for rental. If you are looking to rent a reservation FROM a dvc member, you need to reply into an existing Points for Rent thread.