Changes to Commission Decision of 14 November 2012 concerning the technical specification for interoperability relating to the ‘operation and traffic management’ subsystem of the rail system in the European Union and amending Decision 2007/756/EC (notified under document C(2012) 8075) (Text with EEA relevance) (2012/757/EU): Commission Implementing Decision (EU) 2020/783 of 12 June 2020 amending Decision 2012/757/EU as regards measures to adapt the frequency of periodic medical examination of railway staff undertaking safety-critical tasks other than train drivers due to the COVID-19 pandemic (Text with EEA relevance)