Arielle Green, a publicist in Manhattan, knows what most of her friends earn, whether it is $28,000 a year or $100,000. And she does not seem particularly shy about disclosing her income ($30,000 a year, plus overtime).

At 22, Ms. Green, like her friends, is less afraid to flirt with what many over 35 consider the last taboo in American life: discussing salary openly with friends and colleagues. ''There's just more of a feeling of openness in discussing what you make,'' Ms. Green said..

Her friends, she said, consider frank talk about income a valuable tool. It helps them strategize -- when to push for a raise, when to start looking around. It even helps them figure out plans for a Friday night, whether the assembled cast is better suited to a brick-oven pizzeria or Buddakan.

Yes, elders find it strange. ''My parents wouldn't have this conversation with friends,'' she said. For them, Ms. Green said, ''it's very hush-hush. You don't talk about money, politics, or religion with friends. But in this generation, it's important.''

For people old enough to remember phone booths, a blunt reference to salary in a social setting still represents the height of bad manners. But for many young professionals, the don't-ask-don't-tell etiquette of previous generations seems like a relic.

For them, salary information is now fair game, at least among friends. Many consider it crucial to prosper in an increasingly transient, winner-take-all workplace -- regardless of the envy that full disclosure can raise. Besides, when the Internet already offers a cornucopia of personal information, it almost seems coy to keep personal income private.

As Ilana Arazie, 32, an online video producer for a media company in Manhattan, said, ''If we can talk about how many orgasms we have with our mate, why can't we discuss how much we make?''

While salaries may be disclosed casually among friends, that doesn't mean most young professionals brag about their incomes at a cocktail party. There is still an etiquette to sharing the information -- a proper way to divulge.

For instance, most young people don't tell their cubicle mates, according to a 2007 study for Money magazine by the sociologist Jeanne Fleming and the writer Leonard Schwarz.

Still, young workers seem somewhat less likely to adhere to this convention than older ones. The study found that 90 percent of those over 35 who were surveyed agreed with the statement ''you should never let your co-workers know how much you make,'' while 84 percent of subjects under 35 agreed.

But between friends almost anything is fair game. Beth Kobliner, the author of the best-selling ''Get a Financial Life: Personal Finance in Your Twenties and Thirties,'' said she had noticed that many young people now ''have no idea what their boomer parents earn, but know every intimate detail about their close friends' salaries, 401(k)s and debt loads.''

She attributes the increase in openness in part to a shared sense of struggle by people in their 20s, who have come of age in a turbulent economic time, gyrating from the dot-com boom to the post-Sept. 11 gloom, to the housing bubble to the credit crunch.

''There is a bunker mentality,'' Ms. Kobliner said. ''They've had it rough, jobs are precarious and debts are outrageous.'' Bill Coleman, the chief compensation officer of Salary.com, which tracks income figures for numerous occupations by ZIP code, said that he had noticed more candor about income among those who live by social networking than among those who don't -- what he calls the ''MySpace/Facebook rift.''

And, he said, the new openness on salaries is reflective of a deeper acceptance of networking, offline as well as online.

''This is a generation that is much more attuned to teamwork, collaboration and sharing information,'' he said. ''Everything they do is a kind of group event. How do you know, when you get your first job offer, if $45,000 is a good offer, a bad offer or an O.K. offer? You go to your friends.''

Such was the case with Jim Wang, 27, until recently a software developer living in Columbia, Md., who blogs about his personal finances. Two years ago, he said, several of his friends who worked in the same industry started to get restless. As they started to scout around, they also started to dish.

''People started leaving firms to go to other companies, and they were getting 15, 20, 25 percent raises,'' recalled Mr. Wang, who can name what his 30 or so closest friends earn ''within a bandwidth of $5,000.''

''I thought, why not go out and see what my true market rate is? I found out that there were two companies both willing to pay 18 percent more, so I left.''

Several workers under 35 said that greater salary transparency among friends only makes sense in an age when there is so much information freely available online. Young professionals, in fact, have all sorts of ways to find out how much their friends make, even without asking. Associates at law firms anonymously report their own salaries to Web sites like www.greedyassociates.com. Every bonus season, Wall Street analysts send one another Excel spreadsheets, based on published reports and word-of-mouth, that detail which banks are paying what.

Related taboos already started to crumble over the last decade, as housing prices exploded, particularly in cities like New York and San Francisco, and people suddenly started to consider it innocent dinner-party banter to ask someone, to the dollar, what they paid for their two-bedroom condo.

Rebecca Geller, who works in media relations for green technology companies in San Francisco, recalled a recent brunch with two friends. One, a school administrator, was hoping to find a new job that paid at least $40,000 a year. He wanted to know if the other two people at the table -- Ms. Geller, 29, and a first-year lawyer -- thought he was lowballing himself, asking, ''Why, what do you guys make?''

The truth hurt. The lawyer, a bit sheepishly, admitted that he made $130,000.

''There was definitely an awkward silence,'' Ms. Geller said. Many professionals interviewed said that they believe salary talk is best confined to friends within the same tax bracket, to spare feelings. Others, however, insisted that a little generosity by the haves could help stave off jealousy by their have-not friends.

Some young Wall Street professionals said that since everyone knows everyone else's bonus, it is common for friends with the biggest paydays to celebrate by picking up the check at a restaurant or nightclub.

Still, there are good reasons that generations of parents have instructed their children to keep quiet about money, social scientists say. In a meritocratic country, money has always been the great divider, the primary way Americans connote status.

Thus it is impossible to engage in a conversation about income that is entirely innocent, said Herb Goldberg, a clinical psychologist in Los Angeles who has written about financial issues.

''When people talk about money,'' he said, most people traditionally have presumed that there is ''a motive behind it, and the motive is what makes it seem impolite.'' People bombarded with unwelcome salary information, or pressed to disclose it, assume someone is raising the topic to subtly brag, or put someone else down, he said.

But social scientists say that some young people have generation-specific motives for broaching this touchy subject.

Robert H. Frank, an economics professor at Cornell, said that an open flow of information is deemed crucial by young professionals who think of themselves as free agents, not company men.

''People move between jobs a lot more now than they used to,'' Dr. Frank said. This mobility alone increases the instances that salary might come up among friends.

''If you change jobs, that's news,'' he said. ''If you get a better salary, that's the explanation of the news: 'They're paying me 80 grand, the last place only paying me 65.' ''

Barbara W. Keats, an associate professor of management at Arizona State University who studies money attitudes among the young, said that their relative lack of manners regarding salary can be traced to the self-esteem movement embraced by baby boomer parents.

''As they moved through primary and secondary school, the focus was always to avoid anything that might stifle their creativity or hem them in,'' she said, which has bled into their sense of etiquette. ''They're special, and however they say things is very cute.''

Elders who equate openness with rudeness are missing the point, said Kate Hubin, a 28-year-old publicity director for a film studio in Los Angeles.

''For my generation, salary is one piece of the job satisfaction and self-worth puzzle, but not the only metric we use,'' she wrote in an e-mail message. ''Status is not just about money any more. Everyone knows you generally have to suffer to make a big income, so high-earners talk about their salary in the course of complaining -- is all this worth $180,000? -- while low-earners see their paltry salaries as a token of lifestyle freedom.''

In recent years, even some people over 35 have started to call for more candor on the topic. In a much-discussed appearance on ''The View'' last year, the personal-finance author Suze Orman, a proponent of people sharing salary figures as a means of fighting income disparity, challenged her fellow hosts and other guests to disclose their salary on the show (none did).

Some young professionals seem more receptive to Ms. Orman's logic. Janet Polli, 32, who lives in Ditmas Park, Brooklyn, works in sales and marketing for a nonprofit organization. A few years ago, she and a colleague were both selected for a promotion at a nonprofit, and Ms. Polli suggested they share salary information as a negotiating tool.

''I wanted to be open, like a union,'' she recalled. ''We would get more if we were together.''

But the other woman ''was very secretive in her negotiations,'' she said. ''In the end, neither of us did very well.''

Copyright 2008 The New York Times Company