Ethnicity Question for Common App

<p>So when it says to "describe your background" as part of the race/ethnicity part of the App, is that line the place to describe your ethnicity in greater detail than broad terms like "white" or "Asian"? Also, would being from a rather original white or Asian ethnicity be a slight booster for HYPMS admissions, especially if the university doesn't have or has almost never had students of that particular ethnicity?</p>