Fortunately in a dress-down town like Annapolis, it's easy to get away with Docksiders and dungarees in the office any day of the week.

Still, image experts say the cost for dressing down too much even on "Casual Fridays" can be a mark against you no matter what industry you're in.

"A lot of companies have found that with casual Fridays the dress has gotten sloppier and so has their work," said Dallas-based business etiquette expert Colleen Rickenbacher, author of "Be On Your Best Business Behavior." "A lot of companies have gotten back to a business dress. Some have created an office casual dress code," she said.

The trend toward casual dress has become more evident over the past decade. The casual dress policy at Northrop Grumman's Electronic Systems Sector in Linthicum was limited to Fridays in 1997, but expanded to five days a week in July 2000.

Fridays around ARINC tend to be pretty casual because most employees work flexible schedules that give them every other Friday off.

Chance Walgran, manager of Laurance Clothing, a popular men's clothing store in Annapolis, is even known to come to work in "a bow-tie and flip-flops."

Image experts offered up ways to keep things professional even in a laid-back town. Sandy Dumont, executive director of the Norfolk, Va.-based Impression Strategies Institute, said dressing too casually can make men look "slouchy" and women look "cheap." To avoid the I-just-rolled-out-of-bed-look on Fridays, men should switch from baggy khakis and polo shirts to dark trousers along with cotton dress shirts, she said.

"It announces 'I'm dressed down, but I'm still professional,' " she said.

"Club attire" and bare arms are always a no-no for women no matter what day of the week, Ms. Dumont said. Women should opt for skirts or slacks with a belt for a pulled-together look, Ms. Dumont said. Women should also have a touch of professional makeup, she said, adding that those who do tend to earn more and are considered more intelligent.

Ms. Rickenbacher said her ground rule for casual Fridays is simple: If you have to think twice about what you're wearing "don't go there."

Tiny upgrades can also make a difference. If open-toed shoes are acceptable, make them leather, which is a little dressier, she said. Collared golf shirts should be tucked in with a nice belt to match shoes, she said. Some officials from Annapolis companies said they adjust their dress depending on whether they are meeting clients.

Hollis Minor, owner of The Minor Group, an Annapolis company that offers organizational and business development services, said her dress policy is "when in Rome." For example, Ms. Minor said she'll be dressed to impress in a "power suit" - in dark navy or black - when meeting with clients in Washington, D.C. But if she's not expecting clients, her employees are fine to come in casual.

Just in case, Ms. Minor said she always has a jacket in the back if a client drops in unexpectedly when she plans to be "glued to the screen" writing all day.

"Clients tend to judge based on a traditional form of dressing," Ms. Minor said. "It still sends a message."

The trend toward casual wear has taken shape over the past decade as more formal policies have gone out of style. Loralee Schrand, human resources director of the ARINC corporate and northeast region, said she remembers the unwritten rules banning open-toed shoes and requiring pantyhose, which has changed.

"Back in the day, you couldn't even wear a suit that had uncovered buttons if you were a woman," she said.

Lisa Shea, director of human resources and employee relations at Northrop Grumman's Electronic Systems Sector, said the company's casual-dress policy also has become a recruiting tool.

"It's just the mindset for the folks that are coming out of schools," she said.

Casual dress has become so mainstream that dressing up can mean looking out of place.

Jeff Denman, co-founder of Boucher and Denman, a law firm in Annapolis, recalled the time when he met with AOL as a former lawyer with Arnold and Porter LLP, and was the only person not wearing khakis. At Boucher and Denman, he maintains a business-casual dress code unless he's in court.

"We do that because it's how our clients dress," Mr. Denman said.

Mr. Walgran of Laurance Clothing, which recently became a dealer for the Atlantis WeatherGear clothing line, said the trend toward casual wear also has increased as suits have gone out of style. Offices have evolved to dressing appropriately for any given day, he said.

When he was handling health plans for large corporations and visited clients in the coal mines "you can bet I wasn't wearing a suit and tie." But he said an appropriate office environment doesn't just mean jeans and a T-shirt either.

"I think you always want to be tasteful," he said.