Extensible Business Reporting Language, the much-touted and little-used computer language the Securities and Exchange Commission hopes will revolutionize financial filings, takes another big step forward this week with the debut of its latest incarnation.

SEC Chairman Christopher Cox is set to announce a new “taxonomy” of XBRL terms used to classify financial data—which, in theory, should make today’s text-laden financial reports far easier to present and read online. The taxonomy contains 15,000 elements, compared to only 2,500 in XBRL’s previous incarnation, and will be open for technical scrutiny as of this week.

Cox has been pushing XBRL as the next big thing ...