STYLE AND PRACTICE OF THE CURIA. — These are two canonical legal institutions that differ very little from one another and are relevant in the Code of Canon Law as norms to be applied in cases of legislative lacunae.
The first (style), from a formal standpoint, refers to the forms and solemnities uniformly observed in the performance of ecclesiastical acts by ecclesiastical public authority. When it concerns the norms used in the congregations, tribunals, and offices of the Holy See, it is referred to as the Style of the Roman Curia. From a material standpoint, it refers to the principles consistently observed in the execution of certain acts or decisions, predominantly judicial in nature. The second, namely practice, in the strict sense coincides with style taken in the material sense; in a broader sense, it is equivalent to style. The two terms are sometimes used in an even narrower sense, in which case style indicates the customary formalities employed in the granting of graces; formal forensic usage, indicates the same formalities observed in contemporary matters; practice then designates style in the material sense, that is, decisions in matters of grace and contentious cases. In contentious matters, uniformly decided cases are also called formal forensic usage in the material sense, or the authority of things perpetually similarly judged.
As has been stated, a style and a practice of the Curia in general are distinguished, as well as a style and practice proper to the congregations, tribunals, and offices of the Holy See (Style and Practice of the Roman Curia). As a general rule, style has the force of law: this refers to style in the formal sense.
Although the Code of Canon Law does not mention the style and practice of local diocesan curiae, both can be invoked not to supplement a defect in a universal law, but only to fill lacunae in a particular diocesan law. This is by analogy. The Code of Canon Law, in fact, treats of the style and practice of the Roman Curia where it discusses the usus suppletorius (can. 20). Since law, although drafted in general and abstract terms, cannot foresee and regulate all concrete cases of social life, the opportunity and necessity arise to establish particular norms that indicate the means by which deficiencies and shortcomings of written norms may be addressed (the so-called problem of legislative lacunae, which receives particular solutions varying from one legal system to another). And since this serious problem also exists in canon law (v. INTERPRETATION), the ecclesiastical legislator, among other subsidiary sources, has expressly indicated in can. 20 the style and practice of the Roman Curia. These can produce legal effects only when certain conditions concur, namely: 1) the absence of legal provisions for the concrete case, rendering the application of subsidiary norms indispensable; 2) that such application is lawful. Recourse to subsidiary sources is expressly excluded in penal matters (unless it concerns the application of penalties), regarding singular rights, privileges, and in general, in cases where extensive interpretation is not permitted (can. 19, 983, 2219 § 3).
The style and practice of the Roman Curia are not based on any legal norm but are applied only when recourse to analogy, both in law and in fact, proves insufficient. A distinction is usually made between legal style and factual style. The former is true supplementary law. Judicial decisions and administrative acts (decrees, decisions), although they cannot produce new general law, can be taken into consideration when norms can be derived from them to resolve particular cases in the absence of legislative provisions, thereby becoming binding. Hence arises forensic usage and the authority of things similarly judged, especially from the Apostolic Signatura and the Sacred Roman Rota. The latter, however, is not true subsidiary law, as it imposes binding and obligatory norms only upon the officials of the Curia in the execution of their office. This also occurs in the case of the exercise of delegated power, with regard to the validity of acts.
A question of particular importance and debated in doctrine is whether style can give rise to customary norms. In less recent authors, it is asserted that judicial decisions alone can give rise to custom. But according to better doctrine, the judge, inasmuch as he has limited power to affirm what the law is between the parties, with his decisions, however often he repeats them, cannot constitute law properly speaking. And therefore, the practice of the Curia and tribunals acquires the force of customary law only when it appears from the circumstances that the people to whom the adjudicated matter pertains conform to it, observing it as a legal norm for a certain time, thereby forming custom with the concurrence of other conditions. Only then can it be said that those decisions produce law properly speaking, not by their own force, but by virtue of the rooted custom of the people, of which the judges themselves are a part (v. JURISPRUDENCE).