Consuetudinary (Medieval Latin consuetudinarius, from consuetudo, custom) is a term applied to law where the rule of law is determined by long-standing custom as opposed to case law or statute. Most laws of consuetudinary basis deal with standards of community that have been long-established in a given locale. However the term "consuetudinary" can also apply to areas of international law where certain standards have been nearly universal in their acceptance as correct bases of action - in example, laws against piracy or slavery (see hostis humani generis). In many, though not all instances, consuetudinary laws will have supportive court rulings and case law that has evolved over time to give additional weight to their rule as law and also to demonstrate the trajectory of evolution (if any) in the interpretation of such law by relevant courts. In common law legal systems, a precedent or authority is a principle or rule established in a previous legal case that is either binding on or persuasive for a court or other tribunal when deciding subsequent cases with similar issues or facts. The general principle in common law legal systems is that similar cases should be decided so as to give similar and predictable outcomes, and the principle of precedent is the mechanism by which that goal is attained. Black's Law Dictionary defines "precedent" as a "rule of law established for the first time by a court for a particular type of case and thereafter referred to in deciding similar cases." common law precedent is a third kind of law, on equal footing with statutory law (statutes and codes enacted by legislative bodies), and regulatory law (regulations promulgated by executive branch agencies). Stare decisis (Anglo-Latin pronunciation: /?stri dsa?s?s) is a legal principle by which judges are obliged to respect the precedent established by prior decisions. The words originate from the phrasing of the principle in the Latin maxim Stare decisis et non quieta movere: "to stand by decisions and not disturb the undisturbed." In a legal context, this is understood to mean that courts should generally abide by precedent and not disturb settled matters. Case law is the set of existing rulings which have made new interpretations of law and, therefore, can be cited as precedent. In most countries, including most European countries, the term is applied to any set of rulings on law which is guided by previous rulings, for example, previous decisions of a government agency - that is, precedential case law can arise from either a judicial ruling or a ruling of an adjudication within an executive branch agency. Trials and hearings that do not result in written decisions of a court of record do not create precedent for future court decisions. Piracy is typically an act of robbery or criminal violence at sea. The term can include acts committed on land, in the air, or in other major bodies of water or on a shore. It does not normally include crimes committed against persons traveling on the same vessel as the perpetrator (e.g. one passenger stealing from others on the same vessel). The term has been used throughout history to refer to raids across land borders by non-state agents. Piracy is the name of a specific crime under customary international law and also the name of a number of crimes under the municipal law of a number of States. It is distinguished from privateering, which is authorized by national authorities and therefore a legitimate form of war-like activity by non-state actors. Privateering is considered commerce raiding, and was outlawed by the Peace of Westphalia (1648) for signatories to those treaties. Those who engage in acts of piracy are called pirates (Freebooter.) Historically, offenders have usually been apprehended by military personnel and tried by military tribunals.