if one interface in a zone and another in self zone then traffic can flow right?

poguy

if one interface in a zone and another in self zone then traffic can flow right?
I'm confused with the statement:

If one interface is in a zone, and another interface is not in a zone, traffic may never flow between them

BUT an interface by default is in self zone, isn't it.
So that statement is true if we explicitly pull the interface out from the self zone?
Thank you

broc

An interface is not in the self zone by default, the self zone is the router itself ie communications destined for the router. No interface can be a member of the self zone.