Is it okay to dress for work in chinos and a polo shirt? How about showing up with a pierced nose and torn jeans?

Dressing for success has never before been fraught with so much confusion, contradiction and consternation. The advent of casual dress and its creep from a Friday-only perk to an every-day expectation has left many businesses wondering how to apply the concept and still present a professional image to the working world.

From coast to coast, companies are learning that personal style sense does not necessarily equal common sense. The answer, say human resource experts, is to create a clear yet flexible dress code. In fact, experts say, a clear dress code policy can make everyone feel more comfortable.

Since the early 90s, work-wear has become an increasingly fluid concept. Baby Boomers shifted the workplace away from tailored jackets and broad-shouldered power suits towards relaxed-fit khakis and button-down shirts. By the dotcom boom, preppy chic had given way to grungy garb: message T-shirts and tennis shoes.

The Society of Human Resource Management estimates that as many as 50 percent of all companies now opt for a "business casual" policy on a daily basis, up from about 33 percent of companies two years ago.

The thinking behind such policies is to create a relaxed and happy workplace where individuality is accepted and where skill and talent are given a higher priority than wardrobe. Plus, it's a relatively inexpensive perk that can instantly spread goodwill in the workforce.

The problem for many companies, however, was mistakenly assuming that dress code leeway simply meant eliminating the rules. Hence, the rise of the office grunge look, tattoos and piercing.

The result is that dress codes are returning, even when they are simply setting the boundaries for casual wear.

"I think it's time for most businesses to move back from the far extreme and find a more middle ground on casual wear," said Westaff's Human Resources Representative Gail Jern, who predicts the pendulum is swinging back a notch on casual wear.

In the midst of all this flux, one way for companies to go is with a policy that is flexible enough to accommodate its different needs, and helps the company achieve the right image among its customers, clients and employees. It should also spell out fashion mistakes that take casual wear a step too far: halter tops, blue jeans and athletic shoes. Employees who work in a cubicle and never interface with the public might have the option of more casual wear at the manager's discretion. While staff who work more frequently with clients and customers might ratchet up the professional look.

Staffing agencies can help achieve the right look by ensuring that temporary employees meet the dress code requirements of clients. It's best, Jern said, if companies have a clearly expressed policy that they can share with their staffing company. For some businesses, safety concerns can also come into play. It's a good idea to discourage loose-fitting clothing, for example, if it can lead to on-the-job accidents.