Answer: The document that represents the wishes of an individual regarding end-of-life treatment is commonly known as an "Advance Healthcare Directive" or "Living Will."
Explanation: An Advance Healthcare Directive is a legal document that allows an individual to specify their preferences for medical treatment, particularly in situations where they may not be able to make decisions for themselves due to illness, incapacity, or being in a terminal condition. This document typically outlines the individual's desires regarding life-sustaining treatments, organ donation, and other medical interventions.