Mainstack Substack clarification

[Mark Swindell]

I'm just clarifying for myself what happens to a stack when its  Main  
Stack property is changed.

Scenario:
Main stack "YellowStack" is opened and saved.
Main stack "BlueStack" is opened and saved.

Now, in BlueStack's stack inspector I change its MainStack property  
to "YellowStack."  BlueStack is "subsumed" as a substack of   
YellowStack, while its original incarnation, BlueStack, remains on  
disk as a main stack, in its last saved state?

Is this accurate?

Thanks,
Mark