How does Princeton define an International Student?

What constitutes an international student during the application stage in Princeton’s eyes? I apologise in advance if this is an idiotic question, but I haven’t been able to find a clear answer online, and I am cognizant of the small percentages of international students that Princeton (and indeed any other elite Ivy League institution) admits.

The reason why I’m asking is because I am a US citizen (born in the US, lived in Michigan for 8 years), but for the last 10 years I have been living in Australia, and attending high school in Melbourne. Would this confine me strictly to an international pool, or is there some sort of third category of consideration for a US national/ dual citizen attending high school overseas?

Thank you in advance!

Princeton considers you a US dual resident, the same thing as Harvard: http://talk.collegeconfidential.com/harvard-university/1802614-how-does-harvard-define-an-international-student.html#latest