I read this article about suit buttons: https://www.insider.com/suit-button-rules-bottom-top-2017-3Seems like there's no clear consensus.Also, one button jackets seem like a (rare) thing: https://thesharpgentleman.com/wp-content/uploads/2015/02/one_button.pngMight see if I can get one of these if I ever get a new suit. Looks clean.