An open container offense is considered to be a "petty offense" and as such has not been classified as a crime (either misdemeanor or felony); it is a "violation". In New York, such violations are automatically sealed and it is illegal to report such violations to an employer on a background check. However, even if this violation is sealed to the public, typically the government or military has access to such records. I would hire a criminal defense attorney. If they can resolve this situation some other way you may not have to worry about your guilty plea. A preferable result could be a dismissal or an adjournment in contemplation of dismissal (ACOD). The latter result means that if you stay out of trouble for six months then the case is dismissed.