Great dress codes allow for everyone's freedom: the person wearing the clothing gets to freely express themself, and the people looking at the person are not terribly distracted by the suggestiveness of what they see. Simply put, no cracks, no cleavage, no terribly off color slogans or words imprinted -- think "see no evil. "
It's smart to dress for success. If you want respect, dress like you deserve it, in fashionable, neat, respectable clothing. Don't dress down even if others do. It will make you feel more productive, too!
A smart dress code is a term that refers to various styles of dress yet with a added flare of what is perceived to be "smart" enough for Western cultures. Often this is done by wearing a casual business style and adding such elements as a jacket over top of the item.