If everyone who drank while underage was excluded from employment, most people would not have jobs. No reason to disclose this. In fact, it is Normal behavior.
The response given is not intended to create, nor does it create an ongoing duty to respond to questions. The response does not form an attorney-client relationship, nor is it intended to be anything other than the educated opinion of the author. It should not be relied upon as legal advice. The response given is based upon the limited facts provided by the person asking the question. To the extent additional or different facts exist, the response might possibly change.
This could be a dangerous question for a lawyer to answer. Obviously underage drinking is against the law and if you received a Citation for it I suppose that means something. But my question is were you "convicted" of some type of misdemeanor? And I suppose my second question is what type of job will you be applying for - something with law enforcement?
So, while honesty is usually the best policy, if an application does not specifically say "were you convicted for __________ (anything that is close to underage drinking) then you should omit it from documents.
On the other hand, if you are applying for a job as a bartender - then perhaps putting it on your resume might be a plus. Just kidding. Keep it off your resume and good luck finding employment that you will enjoy!