200Furthermore, the concept of ‘de facto discrimination’ is already employed in EU law, albeit in the field of State aid, for the purposes of finding that a national measure, although not taking the form of a tax advantage derogating from an ordinary tax system, but rather involving the application of a general tax scheme based on general criteria, operated de facto discrimination against undertakings that were in a comparable situation in the light of the objective pursued by that regime (judgment of 21 December 2016, Commission v World Duty Free Group and Others, C‑20/15 P and C‑21/15 P, EU:C:2016:981, paragraph 74).