Brocard

A Brocard is a juridical principle usually expressed in Latin (and often derived from juridical works of the past), traditionally used to concisely express a wider legal concept or rule.

For example, the sentence Inadimplenti non est adimplendum ("One has no need to respect his obligation if the counter-party has not respected his own."), is used in civil law to briefly indicate a principle (adopted in some systems) referred to as the synallagmatic contract.

Some Brocards:

When a rule is clearly intelligible, there is no need of proposing an (usually extensive) interpretation. There can be neither crime nor punishment unless there is a penal law first. What is not reported in the (related, referring) registry, has no legal relevance. Used when a formal act (usually a recording or a transcription) is required in order to give consistance, content or efficacy to a right. When a definitive sentence is declared, it is considered to be the truth. In the case of a sentence in rem judicatam (that finally consents to consider completed a judgement), its content will then be the only legally relevant consideration of a fact. Respect your obligation first, then you can ask for reimbursement. Used in those situations in which one of the two (or more) parties needs to complete his obligation before being allowed to ask for the opposite obligation to be respected by his counter party. Usually this principle is used in fields and subjects in which a certain general steadyness or uniformity of the system has been considered a relevant value by the legislator. The case is typical of service contracts with repeated obligations (like with gas, water, electricity providers and similars), in which irregularities on one side cannot be balanced if not in a regular situation (i.e., of payments) on the other side. The customer, for example, might be asked to pay regularly the new bill, before constesting the previous one in which he found irregular calculations, and asking for a balancement with newer bills; he thus cannot by himself self-determine a discount in the next payment. When the law wanted to regulate the matter in further detail, it did regulate the matter (in the interpretation of a law, an extensive interpretation might perhaps go beyond the intention of the legislator, thus we must limit at what is in the text of the law)

According to the Oxford English Dictionary, the term brocard comes from "Burchard or Brocard", a bishop of Worms in the 11th century who compiled 20 volumes of Regulae Ecclesiasticae ("Ecclesiatical Rules").