Following the Guidelines concerning the exercise of the free movement of workers during COVID-19 outbreak, the European Commission presents the document in the form of FAQ (Frequently Asked Questions).
It contains information for the attention of frontier workers and posted workers affected by the restrictions on free movement of people, being imposed by a number of EU Member States as a result of COVID-19
https://ec.europa.eu/social/BlobServlet?docId=22486&langId=en
https://ec.europa.eu/social/main.jsp?langId=en&catId=89&furtherNews=yes&newsId=9630