A general kinetic feature has been observed experimentally for the oxidation of the sulfur(-II) species thiosulfate, thiourea, thiocyanate, and sulfide by chlorite and other multi-equivalent oxidants under appropriate, unbuffered batch conditions. This "fingerprint" consists of an initial rise in pH followed by an autocatalytic drop in pH or oligo-oscillatory behavior. These systems also exhibit oscillations and other complex dynamical behavior in a continuous-flow stirred tank reactor (CSTR). The previously proposed general models that are oxidant based do not successfully explain the observed pH effects. We propose a simple, general model that is based upon the changing oxidation states of sulfur to explain the general pH features. The scheme qualitatively models autocatalysis and oligo-oscillations in batch and simple and complex oscillations in a CSTR. The general model consists of three separate stages: negative hydrogen ion feedback (S(-II) to S(0)), a transition of S(0) to S(IV), and positive proton feedback from S(IV) to S(VI).