“Curcuscuriaeestlex curiae” is a Latin maxim, which renders the rules of court or the customs of the court, is utmost law of the court. In other words, the practice of the court is the law of the court.There is a debate that the application of rules to cases cannot be completely determined by rules without initiating an infinite regress. In this view, the
habits of courts are part of the law as are the decisions of courts. This applies to courts of equity as well as of common law, even to the High court of Parliament. Although the practice of one court does not govern that of any other, the practice of each court in dealing with its process is unlimited. Such a process will not interfere with positive statutory enactment and a due course of law. However, the court has power over its process, to regulate the manner of execution, that can give order to be done, which should be consistent with the existing law. Otherwise, the process would be abused. The course of the procedure of a court regarding irregularities, nullities, amendments, and other informal proceedings are included under this rule. There are many decisions of the several courts and judges upon the varied and abstruse questions which arise in the application of a law, constantly brought before them, decisions of which are, in fact, law. For example, in the Sri Lankan case ofBoyagodav.Mendis(30 NLR 321), it was settled that where an enactment concerning procedure has received a certain interpretation- which has been recognized by the courts for a very long period of years, the practice-based upon such interpretation should be followed.
By some Acts of parliament, the court has the power to make rules of practice, which become the law of the court. The propriety of such delegated authority may be open to question when it goes beyond mere practice or permitting the changes of positive law. This delegated authority even applied to Parliament, comes within the rule, “Delegatusnonpotestdelegare.” Similarly, the procedure adopted by international actors and institutions form the course of international law. The procedure and course of international law are to be understood jurisprudentially under this maxim rule. The international institution and the court set the tone of international law, in turn forming a part of its practice, ultimately forming a part of international law, such as customary law.