 The parsing of the Bell locality condition as a conjunction of PI and OI is due to Jarrett (1983, 1984), who referred to the conditions as locality and completeness. Jarrett (1983, 1984, 1989) argued that a violation of PI would inevitably permit superluminal signalling. The conclusion requires an additional assumption, that the state of the system be  controllable.[7]  It would not hold for a theory on which there are principled limitations on the ability of would-be signallers to control the states of the systems they are dealing with. Nonetheless, in some of the literature PI has been treated as equivalent to no-signalling. This is predicated on regarding any limitations on control that might prevent a violation of PI from being exploited for signalling involves only practical limitations irrelevant to foundational concerns (see e.g. Ballentine and Jarrett 1987, fn. 6; Jarrett 1989, 70; Shimony 1993, 139), disregarding the possibility of theories involving in-principle limitations on control. 