I think the 4 letter code is simply inacurate in so many ways. I am not asking for a disband of the 4 letter system, but i should be a more concise definition should the user wanted to know more about his type.
Each type should be represented by 2 letter code instead.
The highest scored 2 letters in your MBTI test should be taken out to represent your type.
Here is all my two letter code (each two letter representing a personality) types:
IS - Introverted Sensing
And here are all the types jung never listed: