Takeways from my Tax Notes International column 'A Certain Tax Position', May 7, 2018 Domestic Member State anti-avoidance tax rules may be struck down if they infringe EU laws or principles, like the freedom of establishment Conversely, domestic laws that potentially infringe EU laws or principles may be validated on grounds of preventing tax avoidance Defining tax avoidance for these purposes has proved a difficult job both for the EU Court of Justice and the EU legislator