From bare shoulders in California's Capitol building to Muslim head scarves at Disneyland to no "bling" in the NBA: What's acceptable attire -- or not -- in the workplace is as rumpled as an ill-fitting suit.

It's a problem that has permeated office cubicles and corporate culture for decades.

"There's been a million books written on 'dress for success,' but there's still a lot of uncertainty," said Kimberly Elsbach, a graduate school of management professor at the University of California-Davis.

And as employers have found, it's never easy defining what's appropriate, no matter the workplace.

"It's a minefield as far as misinterpretation or causing bad feelings," said Tom Nearn, operations manager for Generations law firm in Sacramento.

Over the years, Nearn's firm has tried a number of ways to convey what it wanted, including the innocuous advice to "dress professionally." But low-cut tops and leggings worn to work by junior attorneys made him realize an intervention was required. He brought in a professional clothing expert, who met with the firm's attorneys.

The result: "It turned the corner for us as far as good communication on how to dress and project the image you want."

It's not a problem everywhere, of course.

Diane D. Miller, president and CEO of Wilson Miller & Nelson, a Sacramento career and executive coaching firm, said: "We don't find tank tops and cleavage at the executive ranks ... Men and women who are serious about their work make sure they look like it."

But there are generational differences as to what's "appropriate," and there are differences across corporate cultures. The loosened-up environment at Apple or Pixar has completely different clothing requirements than a more button-down insurance or financial services company, Elsbach notes.

"We've had to address low tops, short skirts, tight clothing. Either too much or not enough," said Debbe Dreher, vice-president of Association Resource Center, whose 44 employees are primarily women.

"You don't want to be offensive or critical of an employee," she said, "but at the same time you have to look at the impression they're giving your clients."

Dreher's Folsom, Calif., company is a trade association management firm. She also is executive director of the 700-member Sacramento Area Human Resources Association.

She said most companies have a written policy on dress so the expectations are clear. At her firm, employees whose workday attire is problematic first get an oral warning; if skimpy attire continues, it's written up.

Miller said some companies are dropping their "business casual" policies because employees don't understand the term. "When the staff starts wearing clothes they would wear to the market on the weekends, you've got trouble."