It depends on your geographical area. Down south a woman wearing dress shorts at a modest length can be acceptable or wearing capri's. Sandals without socks or hose is common. Sleeveless tops are OK. (Never tank tops!)

It also makes a difference if your position involes dealing with the public or if you are confined to a cubicle. If a person likes to dress Goth and their job only entails answering the phone at a phone bank it won't matter as much as a phone answerer who is also a receptionist greeting customers at a desk out front.

In most places it means denim or Khaki is OK. Sport shoes, clean and in good condition. Dress t-shirts or Polo shirts. (Nothing with a logo or writing on them!)

It also depends on the type of work you do. At a law office "business casual" may mean you don't have to wear a tie, or that a colored shirt rather than a white one is OK. At an IT business or creative advertising firm, it may signal that "anything goes" and everyone is encouraged to express their personality. A rule of thumb though is that nothing that says *sexy* is appropriate for office attire. Don't wear anything that would be a 'head turner'. You don't want to be know as "That floozy girl with the great va-va-vavoom cleavage." or "That gay guy with the butt hugging tight pants and cowboy boots."

Normally I would say to look around the office and see what others are wearing but you say everyone is doing something different. I would recommend looking at what the people you admire and are successful in their positions, are wearing and more importantly, look to see how your supervisors are dressed and copy it. Just because someone in the office is wearing flip-flops and allowing their tattoos to show, does not mean that the supervisors are seeing this as a positive, and they might be merely tolerating it until they can hire someone else to fill the position.

A bit of advice I read somewhere once said "Dress to the position that you are striving to attain." You don't want your attire to be a barrier to advancement to a better postion. The powers that be are not going to reason it out that once they promote a person that the person will automatically start dressing more tasteful. They are not going to want to go through the hassel of sitting a person down and telling them they will have to ditch to combat boots, black eyeliner and skull hair barrettes in order to accept the promotion. They'll just skip over the person and pick someone else. (In most cases. If you work at the corporate headquarters of Hot Topic it would be different.)

And of course you could always ask your boss what is appropriate where you work.

Well Business Casual is supposed to be 1 step under business attire. It is supposed to be professional , yet laxed. Capris are usually acceptable, BUT it all depends on your department.
In my opinion, if everybody is dressed in semi-business, than you should wear business attire. It sets you apart from the majority and your superiors will have a deeper respect for you as an employee.

Its just hard to assess because every office is different.

The largest mistake I see our younger staffers making is mixing up business casual, with cleaning out the garage casusal !