Flexible and semi-rigid vinyl chloride resin compositions comprising a combination of a latent mercaptan and a zinc salt of oxidized polyethylene as a heat stabilizer are substantially free from the offensive odor typically associated with mercaptans and are protected during processing by the degradation products of the latent mercaptan and the zinc ionomer. Receivers capable of determining the transmitted data values by measuring one or more parameters of an acoustic field are utilized. Preferably, each succeeding security level in the set of security levels is reached as time increases from an idle time associated with the user session. Attributes can be automatically applied to various items using a process that determines aspects of items that are indicative of each attribute being relevant, and automatically applies the attributes to items having at least some of those or similar aspects. An external IO interface is provided for communication with a remote controller.