Unbeknownst to many, the U.S. Supreme Court has been editing its decisions without notice or indication.

These revisions include "truly substantive changes in factual statements and legal reasoning," according to Richard J. Lazarus, a law professor at Harvard University.

Lazarus was originally interviewed about a new study examining this issue by the New York Times.

While the Supreme Court does warn readers that early versions of its decisions, available at the Supreme Court Building and on the court’s website, are works in progress, a small-print notice says, "this opinion is subject to formal revision before publication."

It also asks readers to notify the court of “any typographical or other formal errors," according to the New York Times.

Only four legal publishers are granted access to the pages and what the revisions are.

When the New York Times asked for copies, the Supreme Court refused to provide them.

This issue highlights the need for and eventual use of data and software to track any changes in a public, online record of Supreme Court decisions, according to Alexander Howard at E Pluribus Unum, a blog focused on open government and technology.