Alright, so I got an English oral exam coming up, and I picked the theme ''Mysteries, phenomena and ghost stories''. I then chose to do a presentation about serial killers, those who's identities was never found, so I picked the 2 most interesting and probably most well known, Jack The Ripper and The Zodiac Killer, but that's besides the point. My question is about Jack The Ripper who has killed 5 confirmed victims, who are called ''The Canonical Five'', which I don't understand what it means, and that's my questions, can you give a simple explanation about the definition of it? Thanks in advance.