At this point you can pool any or all of your stockpiled RUs to a world that you own.  This is a convenient way to gather all of your RUs in one place and then disburse them as you see fit.  RUs at blockaded worlds cannot be shipped off-world for pooling purposes, but RUs can be pooled to a blockaded world.
 

Abandoned Empires: Abandoned empires pool RUs at the owned world with the highest friendly-DP-to-foreign-gun ratio.