Well, when the project was actually done with the rules of the Senate, the index, which was originally 102 pages long, was reduced to 22 pages. The reason was that there was an integration of the marginal notes and the headers and subheaders that you find in the table of contents. That was used as a guide to create the index. As a result, it was simplified.
On April 9th, 2019. See this statement in context.