Bring the discharge letter to show them in case they hassle you about the discharge. If the interviewer doesn't understand the codes, they can take a copy of the letter and ask a supervisor or one of their legal staff after the interview is done.
Thanks Jack for your response. I attached a copy of the discharge letter and a copy of the envelope that contained it to my N-400 package sent couple months ago and I will definitely carry the original with me to the interview.