N. Notes

This ap­pen­dix col­lects var­i­ous notes on the ma­te­r­ial. This sort of ma­te­r­ial is of­ten given in foot­notes at the bot­tom of the text. How­ever, such a foot­note is dis­tract­ing. You tend to read them even if they are prob­a­bly not re­ally that im­por­tant to you. Also, foot­notes have to be con­cise, or they make a mess of the main text.