Normative propositions of the international courts, including these of the International Tribunal for the Law of the Sea, are considered in the paper as provisions in the judicial decisions and advisory opinions, spelling out, formulating or describing international law norms, prescriptions, prohibitions or authorizations, which are applicable, in the court’s view, in the case at hand and the similar cases. Such a proposition is considered to be a description of a legal norm, its spelling out by a court, but not a norm or its source. In contrast with legal norms, judicial normative propositions are descriptive, not prescriptive; they may be true or wrong. Normative propositions are not transformed into norms solely by their repetition in judicial decisions. The author considers not only ITLOS decisions but also the Tribunal’s and its Seabed disputes chamber advisory opinions containing normative propositions to be subsidiary means for the determination of the rules of law under article 38(1(d)) of the International Court of Justice Statute. The legal reasoning of the Tribunal’s decision, not its operative provisions, usually features normative propositions. While strictly speaking, the decision addresses the parties of the dispute, normative propositions in the reasoning are in fact enacted by the Tribunal urbi et orbi aiming at all relevant actors, ITLOS including. They bear upon substantive and procedural issues, rights and obligations of relevant actors; they may also define legal notions. The Tribunal provides them as part of its reasoning or as obiter dictum. It is those provisions of the Tribunal’s decisions that are of particular importance for international law through detailing treaty- and verbalizing customary rules. However, the States that have the final and decisive say confirming or non-confirming the content and binding nature of the rules spelt out or described by the Tribunal in its normative propositions. Meanwhile, States are not in a hurry to publicly react to the judicial normative propositions, particularly to those of ITLOS, though they refer to them in pleadings or when commenting on the International Law Commission drafts. At times, States concerned argue that international judicial decisions are not binding for third parties. While the States are predominantly silent, ITLOS reiterates, develops and consolidates normative propositions, and they begin to be perceived as law. The paper also points to the possibility of the Tribunal’s normative propositions being not correct and to the role of the judges’ dissenting and separate opinions in identifying such propositions.