45As the appellant states, the principle of legal certainty is, according to the case-law, a fundamental principle of EU law which requires, in particular, that rules should be clear and precise, so that individuals may be able to ascertain unequivocally what their rights and obligations are and may take steps accordingly (see, to that effect, judgment of 14 April 2005 in Belgium v Commission, C‑110/03, ECR, EU:C:2005:223, paragraph 30 and the case-law cited).