Following are the four "Master Quality" (MQ) categories of high-resolution audio, which were formalized by the major record labels in 2014. See
high-resolution audio,
PCM,
analog,
CD and
DSD.
Category Sound Source
MQ-P PCM (minimum 48 kHz/20 bit)
MQ-A Analog
MQ-C Compact Disc (CD)
MQ-D DSD/DSF (2.8/5.6 MHz)