The JI designation is just a leftover from the days that Midway was known as JET EXPRESS in Chicago. When the airline was brought to RDU, only the airline name changed but not the JI designation.skydiverdriver said:Yeah, I've been meaning to call you. Just a suggestion, please use codes that most people know. I've been involved in aviation for over twenty years, and I have never heard of ji, and some of the other ones people use. I guess that is unless you only want people who worked there to know what you're talking about. Just a suggestion.