From ABA Journal:

The R Street Institute, a public policy organization in Washington, D.C., and others argue in their brief that official annotations have been part of the law going back to China in the time of Confucius, the Roman Republic and Empire from 450 B.C. through the Justinian codes several hundred years later, and England in the 15th century and later.

“From the beginning, nonbinding commentaries and annotations have carried legal weight,” the brief says.