About 40 companies already are voluntarily experimenting with extensible business reporting language, or XBRL, which tags individual financial items such as revenue.

Mandatory use of the tags, akin to bar codes for financial data, could be next: the Securities and Exchange Commission may issue such a proposal this spring and vote on finalizing it this fall, SEC corporation finance division director John White told a legal conference at Northwestern University.

White cautioned that "a lot has got to happen" before U.S. regulators would require data tagging, including modifications to Edgar, the SEC's electronic database, and acceptance of recently issued common definitions for items to be tagged. Despite such hurdles, an SEC advisory group has recommended that the agency phase in a move to data-tagged reports by public companies.

"This is real, it's happening," White said.

Updated SEC staff guidance on corporate Web sites and blogs also could be coming. White said given changes in electronic communication and technology, regulators are "looking seriously" at revisiting guidance the SEC issued in 2000.

SEC rules on accounting for oil and gas reserves, which date from the 1970s, are getting a second look as well. White said the current requirements are out of date, prompting the SEC to seek public comment on possible updates. White said the SEC could consider rule changes this spring and look to complete them in the fall.