IEC 61937-1:2021 is available as IEC 61937-1:2021 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.

IEC 61937-1:2021 applies to the digital audio interface using the IEC 60958 series for the conveying of non-linear PCM encoded audio bitstreams.
It describes the way in which this digital interface can be used in consumer applications. The professional mode is not considered within the scope of this document.
IEC 61937-1:2021 cancels and replaces the second edition published in 2007, and amendment 1 published in 2011. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) Activation of Pe field;
b) Enhanced usage of channel status bits.
c) Addition of Annex B.