Smart casual is preferred, but regular work/street/leisure/office attire is  appropriate; we want you to feel comfortable and relaxed.  Dressy or special occasion attire is also appropriate.

However: 

We cannot allow bare feet, and do not recommend flip-flops for safety reasons.

Also: 

Gentlemen:  Please, no sleeveless muscle shirts (or we will have to provide you with one of our tee-shirts to wear while dining).

Ladies:  Please, no short shorts, short short skirts or bare tummys.