Accounting regulators have fired what they say is the last salvo in a decades-long war to require companies to expense their stock option grants, setting the stage for the next battle -- exactly how to do so. The Financial Accounting Standards Board, or FASB, an independent regulatory body that sets financial accounting rules, has said that by the end of this year, it will pass a new rule forcing companies to count their option grants as a cost, and expense them as such. The goal is twofold: clean up the messy accounting that surrounds such option plans (for instance, companies that argue the options are not a cost still happily take the tax break associated with them), and provide shareholders with a clearer picture of what the actual cost of such plans are and how dilutive they can be. Companies are currently able to treat stock options as an expense if they so choose. However, few do. Notable exceptions are General Electric ( GE), General Motors ( GM) and Coca-Cola ( KO). Otherwise, all that's currently required of companies is that they annually provide a pro forma (in other words, hypothetical) accounting of what earnings per share might look like if the company expensed its options. You can find this information in the footnotes of the annual report. "That always gets buried," says David Veeneman, a benefits consultant in Chicago. "Even if you know what you're looking for, it can be tough to find." At the behest of corporate lobbyists, many in Congress have attempted to stall FASB's plan to require that companies expense their option packages. But most observers say it's only a matter of time before companies will have to deal with a new policy, so rather than debating when or why, the debate should center on how. Few disagree that options do indeed have a cost to the company. The problems arise when trying to decide how to ascertain that cost.