Here are the venues that have posted dress codes (some more vague than others):
Margaritaville Las Vegas – Casual
Palms’ Fantasy Tower – Stylish Nightlife Attire (no hats, no tennis shoes, no baggy or torn jeans, no sandals for men.)
JET at The Mirage – Casual chic. No tank tops, athletic wear, track suits or shorts. Fashionable sneakers will be allowed. Dress code enforced.
PURE Nightclub (Caesars) – Casual Chic: Fashionable attire is required. No sports jerseys, tank tops on men, tennis shoes or athletic wear of any kind will be permitted. The dress code is at management’s discretion.
Shadow Bar (Caesars) – Casual
Casa Fuente (Caesars) – Casual
Rhumbar at the Mirage – Casual
Vanity Nightclub (Hard Rock) – No tennis shoes
Sushi Roh (Caesars) – Casual
V Bar (Venetian) – No bandannas, tennis shoes, ripped or baggy jeans, athletic attire. Guys avoid shorts, tank tops, sandals.
Hard Rock – very casual
For a list of when the parties are, in addition to who is holding them, check the following site: http://www.securityaegis.com/blackhat-and-defcon-parties/