The recently released S02E03 of Star Trek: Discovery showed operations of Section 31, a secret defence organization of Starfleet. Section 31 was also mentioned in Star Trek Into Darkness movie. Some Star Trek TV series like Star Trek: Deep Space Nine have also mentioned/ shown it. We've also got a question about it.
While exploring more about Section 31, I came to know about Star Trek: Section 31 book series. Before I read it, I want to know whether it is canon.
Are Star Trek: Section 31 books canon?