With the dog days of summer comes a hot-weather interpretation of "business casual" at some offices: midriff-baring tops and mini skirts on women and flip-flops and T-shirts on men.

After more than a decade of business casual dress codes at most accounting firms and other companies, employers are starting to wonder how they got to this point. Shouldn't it be obvious that stomachs should be kept under wraps?

Apparently it's not obvious to everyone, and some employers are issuing new guidelines to better define what they mean by "business casual." Some are eliminating it altogether.

Suby, Von Haden & Associates, a CPA firm in Madison, Wis., had a casual dress code on Fridays from 1997 until 2000 but has discontinued it, the Wisconsin State Journal reported.

"Client expectations and meetings scheduled determined that we needed to adopt an 'appropriate attire' dress policy for the entire business week," said Sherry Gustafson, human resources director. "While appearance alone does not guarantee high quality, there is no question that what you wear can have a profound impact on how you are perceived in any business environment," she told the newspaper.

The idea behind those "casual Friday" policies, which extended through the week at many companies, was to create a more comfortable atmosphere. Perhaps if everyone dressed similarly, no matter their position on the corporate ladder, camaraderie and morale would increase. However, one person's idea of comfortable could be another's definition of sloppy.

"I've had clients tell me that it adversely affects their productivity if they see others in the group dressing inappropriately," said Maynard Brusman, president of Working Resources, a workplace consulting company in San Francisco that works with accounting firms, law firms and high-tech companies. "It's wasting their time, they can't focus," he told The Wall Street Journal.

Consider the debate at the Dubuque, Iowa, office of Prudential Retirement. Are capri pants – which the dress policy permitted only on Fridays – the same thing as "cropped pants," which the policy allowed on any day?

"People would get in tiffs about whether they were capris or cropped pants," Judy Lai, a financial analyst, told the Wall Street Journal last summer. "Part of me kept thinking, 'We're going through a lot of stuff at work right now – I can't believe we're wasting time on this kind of thing!' " In the end, management ruled that capris could be worn any day of the week.

It's no wonder that some employees are confused. One way to cut through the fog is to find out if the company actually defines its dress code. (The PricewaterhouseCoopers website, for example, calls its dress code, "modern professionalism, which means that we dress appropriately for the occasion and the business environment in which we operate.")

Another way is to check out the firms' college-oriented websites, which may offer a real-world "day in the life" look at the firm. Deloitte & Touche USA, LLP, offers videos of employees from each of their business units.

Mary Sapp, a senior business economics and Spanish double major at the University of Texas at Austin, told CareerJournal.com, The Wall Street Journal's career site, that videos helped her job search. She said she could see whether women were managing directors, if the dress code was stuffy or business casual and it helped her picture herself working there.

Keep in mind that customs may differ from office to office. Keri Fleming, a human resources manager for KPMG LLP, in Short Hills, N.J., said the dress code is relaxed, in part to offer a more flexible working environment in an atmosphere of severe staffing shortages. "For the most part, business casual is encouraged in our offices," she told NJBIZ.com. "Of course when we're on-site with a client, we follow their style of dress."

Wear what the clients wear seems to be a good rule of thumb for client meetings, where professionalism is paramount. As for the other days, Susan Heathfield, a consultant who specializes in human resource issues, advises: "Clothing that works well for the beach, yard work, dance clubs, exercise sessions, and sports contests may not be appropriate for a professional appearance at work."

She adds, "Clothing that reveals too much cleavage, your back, your chest, your feet, your stomach or your underwear is not appropriate for a place of business, even in a business casual setting."

The days of power suits may be over, but when it comes to skimpy fashions, experts say it's wiser to play it safe.