This is one of my all-time biggest fashion related pet peeves because you have NO idea how many professionals I see screwing this one up. Button-down shirts and button-up shirts are two entirely different terms, and are NOT to be interchanged.
Button-up refers broadly to buttoned shirts. This encompasses dress shirts, sport shirts, hidden plackets, french cuffs, all collar styles, you name it. As long as it buttons shut and is a shirt, it is a button-up shirt.
A button-down shirt is an altogether more specific term and refers to the collar of the shirt, not the closure. Seen most commonly on oxford-cloth shirts, button-down collars are attached to the body of the shirt with - you guessed it - buttons at the points of the collar. GQ actually just published an article about the history of this style (something to do with Polo players and their collars flapping about all nimbly-pimbly), but all I really care about is that you don’t mix the two up.
I bring this up so heatedly because I was just browsing the American Eagle selection (actually, due to another GQ post featuring some of their bright, spring-appropriate OCBD’s) and noticed that they call ALL of their dress shirts ‘button-down shirts.’ Bull. Shit. You people are paid (probably very well) to know what the hell you are talking about. Do your homework, and get it right (and maybe fire that copy-writer and hire this guy? eh? haha).
On a more cheerful note, a little hint of exciting things to come: I just FINALLY ordered a camera capable of producing professional-quality pictures! That means a brighter, better-illustrated Wide Eyes, Tight Wallets coming soon to an internet near you! Who knows, maybe I’ll even go back and update old posts as well. Be excited!