A communication system comprises a multiplicity of slave units and a master unit. Some embodiments of the vapor-emitting devices include intrusive actuation of the end of use indicator, while other embodiments include non-intrusive actuation of the end of use indicator. At a given instant, each timeline marker may appear in a particular one of the multiple display tracks, and the entire collection of timeline markers being simultaneously displayed at that instant may be arranged so that all of the timeline markers appear separately from each other. The schema definition and the at least one model are stored in a data quality model. In a specific embodiment, the first mechanism includes a credit card or Automated Teller Machine terminal, and the account number includes a credit number or ATM number. In accordance with these and other embodiments of the disclosure, a method may include receiving an input for indicating a characteristic of an output load current of a switched output stage comprising at least one driver device and selecting an effective impedance of a gate terminal of the at least one driver device based on the input for indicating the output load current.