Minor alcohol violations are, in my experience, the most common violations. An adcom won't blink if you report being caught at a party where alcohol was served, having someone bring alcohol into your suite, being found drinking in your dorm room. Just state that what happened, accept your share of the blame and report what you learned from the experience or just say, "it never happened again".
The bigger institutional actions such as being expelled, academic dishonesty, and criminal activity (drugs, theft, assault) get the adcoms attention. One time alcohol violations don't.