What exactly is "Limit reinforcements to own units only"?

I have seen this option but have no clue what it means.

It means that if you pick germany, and germany has panzers, you will be able to recruit panzers when you conquer other countries. If another player conquered germany, he will not be able to recruit panzers.

Oh okay thanks

Meester lock topic pls

I summon ~Meester.

Lock.