A dB reference level equal to “Full Scale” or “Full Code.” It is used in specifying A/D and D/A audio data converters, but also increasingly used to refer to signal levels in the digital domain since they are almost always referenced to the full code value. Full scale refers to the maximum voltage level possible before “digital clipping,” or digital overload of the data converter. The actual Full Scale voltage is fixed by the internal data converter design, and varies from model to model. In digital metering a level of 0 dB is ostensibly equal to 0 dBFS, but in reality there may be some “fudge factor” built in either by design or by accident. Nevertheless the two can be thought of as the same thing at a practical level.