Not acceptable (even if you have this stuff for free, you need to wear something else):
-Anything not your size (dad's suit, brother's shoes, the wrong size Armani you bought for $150)
-Anything with a hole or stain on it.
-Bright colors:White suit, red suit, canary yellow
-Any jacket with more than 3 buttons (unless your name is Cedric and you are an Entertainer)
-Mismatched suit separates (no 2 colors, not even blacks, are created equal)
-tuxedo pretending to be a suit
-double-breasted jacket or french cuffs (unless you are that one older applicant who already owns several companies)
-sneakers or "hybrid" dress/casual shoes. No.
-athletic socks
-phone holster
-tag on the sleeve of suit jacket (I have seen this many, many times)
-dark or bright striped shirt (Lee Hotti ftw)
-backpack
Acceptable (if you already have this stuff, there is no need to go buy anything else. You can wear it):
-black suit, or separates
-black shoes
-modern 'nightclub' dress shoes as made by Kenneth Cole, etc (I don't like these but they are very commonplace now, they are acceptable)
-plain white shirt
-sweater over shirt and tie (yes I think this is an acceptable alternative to a suit, others might disagree)
-sports watch
-any kind of venting, or none at all is acceptable
Better (if you have a choice, this is better than acceptable):
-charcoal, navy, or dark brown suit (subtle patterns such as pinstriping or checks are completely fine)
-medium-brown to dark brown shoes with any of the above suits
-solid dress shoes such as made by Allen-Edmonds, Alden, Santoni
-dress watch with a leather strap (not your 500m fake tag heuer diver)
-single vented or double vented jacket
Last rule, don't ever, ever buy something for the label or for the "discount" %.