World’s oldest Torah scroll?

Bologna Torah scroll
This looks like it may be significant. A Torah scroll in the library of the University of Bologna in Italy is thought to be more than 850 years old. A librarian in 1889 had examined the scroll and dated it to the 17th Century. However, a reexamination of the scroll and carbon dating tests have now dated the scroll to be much older, making it the oldest complete text of the Torah known to exist. The script used in the scroll is from the oriental Babylonian tradition.
I’m curious about the “features forbidden in later copies under rules laid down by the scholar Maimonides in the 12th Century”. Are there any Maimonides scholars reading this who can enlighten me?