In Johnson v. Avery (1969) 393 U.S. 483, which section 3163 cites as a reference in the "AUTHORITY" section accompanying the regulatory text, the Supreme Court struck down a Tennessee prison regulation that prohibited inmates from assisting each other with legal affairs. (Id. at p. 484.) While the Court recognized that prison authorities need to be able to administer state detention facilities in an orderly manner that ensures security and discipline, it emphasized the fundamental importance of the writ of habeas corpus and the need to maintain the right unimpaired. (Id. at p. 485.) Therefore, a prison regulation that impairs the ability of prisoners to pursue habeas relief, as the Tennessee regulation did by essentially denying the writ to illiterate or poorly educated prisoners, is invalid (absent adequate alternative protections). (Id. at pp. 485-490).