What is not an official collar shape?

Assuming that your choices are Mandarin, Cinderella, Peter Pan, and Sailor collars, the option which is not an official collar shape is Cinderella, whereas the rest of them truly do exist. Mandarin collar comes from Asia, Peter Pan collar is usually found on women clothing, and sailor collars come from sailor uniforms, but they can be found on regular clothing items too.

Answergiorgio de chirico;