Complex sentence: DSC version 1.2 was released on January 27,2016 and is included with DisplayPort 1.4; version 1.2a was released on January 18,2017.
Split into simpler sentences: DSC version 1.2 was released on January 27,2016 and is included with DisplayPort 1.4. Version 1.2a was released on January 18,2017.