How to setup public location?

[Alexander Belchenko]

Help on push said:

Options:
   --stacked             Create a stacked branch that references the 
public location of the parent branch.


What is public location here? Can you provide some example?

Am I understand correctly that if I want to push branch on LP and want 
to stack it on non-trunk (not focus of development) I need to explicitly 
specify --stacked-on option to desired master branch (e.g. lp:foo/2.0)?