Mandatory XBRL use moved a step closer to reality with XBRL U.S. Inc.'s handover Friday to the SEC of the final drafts of the computer labels that make financial data interactive and increase its transparency. But that action was just a prelude to the anticipated imminent release of a proposed timetable for implementation of eXtensible Business Reporting Language by U.S. public companies. SEC officials have been hinting that a proposal requiring U.S. public companies to use XBRL could be introduced as soon as next Wednesday (May 14), when the Securities and Exchange Commission next meets to consider the future of XBRL. In a speech at a meeting of the American Bar Association last month, SEC general counsel Brian Cartwright predicted that just such a proposal would be released “in the near future.”

Implementation will likely be phased in over two years. Just last week, SEC chief accountant Conrad Hewitt noted that an advisory group suggested that companies attach computer codes to their financial tables, or “tag” the tables and financial statement footnotes in the first year. In the second year, companies could provide detailed tagging of the footnotes. Another advisory committee has recommended that the 500 largest U.S. public companies tackle XBRL the first year, followed by others after initial results are reviewed.

The SEC has encouraged voluntary XBRL filing since April 2005. And earlier this year, the SEC Advisory Committee on Improvements to Financial Reporting recommended to SEC Chairman Christopher Cox that all U.S. public companies adopt XBRL, following a phased-in transition based on company size and reviews of the program's progress.