The things you learn when you double check something you’ve never really thought about such as the difference between button-down and button-up shirts. I’ve always called a dress shirt (besides dress shirt) a button-up shirt. Well, it turns out that’s wrong. A button-down shirt includes the button on each collar to hold it in place (that’s the button-down part). The button-up does not. AND a dress shirt will always have the buttons on the collar. Thus always a button-down shirt. The things authors have to know.
By the way, my mom would always correct me as a kid when I referred to my top as a shirt. She said boys wore shirts, girls wore blouses. I can see that except when it’s a t-shirt. (Of course, the spelling of t-shirt is another argument. ) HA!