The Resident Evil manual is a booklet sold alongside copies of the game. Though there are slight differences between re-releases and ports, the English manual is largely the same. This manual included translations from the BIOHAZARD manual by Tom Shiraiwa, but with original writings by Corey Tresidder.
During production of the manual a number of inaccuracies were made, or otherwise story details fabricated for the benefit of the player. One such example is the consistent misnaming of S.T.A.R.S. as the "Special Tactics and Rescue Squad". Another common error in the manual is its suggestion that S.T.A.R.S. is a crime agency with branches around the United States, rather than being unique to Raccoon City. It further implies that the entire S.T.A.R.S. unit in Raccoon City, save Albert Wesker and Joseph Frost, has only recently been reassigned there, and that the Alpha Team is superior to Bravo Team rather than being equally-qualified and working on a rota system. All these errors made their way into the S.D. Perry novels, as Perry used the manual as a source.
Further errors are present in character biographies. Barry's background has him as a SWAT officer, rather than an Air Force pilot. His serving with Chris in the same unit is not brought up, and it is instead implied he met Chris after the two left. On Joseph's biography it claims he was transferred from the Bravo Team, which is not brought up anywhere else. Further more, Brad Vickers' nickname, "Chickenheart"; Richard Aiken working as radioman for both Alpha and Bravo Team, and Enrico Marini seeing Chris and Barry as threats to his leadership position are also not brought up outside the manual and are canonically dubious.
Resident Evil Sega Saturn manual
Bio Hazard PSX manual