Русско-англо-русский юридический словарь

In contract law, we can sort the rules into two sorts, "default rules" and "mandatory rules."

Here's an example. The Uniform Commercial Code (or UCC, the codified law of contract that applies to contracts between businesses as a matter of state law in the United States) creates a duty to act in good faith--this is a mandatory rule, because this duty cannot be disclaimed by a contractual provision. The UCC also includes an implied "warranty of merchantability," that attaches to contracts, but can be waived by agreement--this is a default rule.

Grasping this distinction is important for at least two reasons. First, unless you know whether a given rule of contract law is a default rule or a mandatory rule, you don't really know the law. And it isn't always clear whether a given rule is one or the other: the usual tipoff is language like, "unless the contract provides otherwise" or "absent an agreement to the contrary." (Legal Theory Lexicon 050: Default Rules and Completeness)

In contract law, we can sort the rules into two sorts, "default rules" and "mandatory rules."

Here's an example. The Uniform Commercial Code (or UCC, the codified law of contract that applies to contracts between businesses as a matter of state law in the United States) creates a duty to act in good faith--this is a mandatory rule, because this duty cannot be disclaimed by a contractual provision. The UCC also includes an implied "warranty of merchantability," that attaches to contracts, but can be waived by agreement--this is a default rule.

Grasping this distinction is important for at least two reasons. First, unless you know whether a given rule of contract law is a default rule or a mandatory rule, you don't really know the law. And it isn't always clear whether a given rule is one or the other: the usual tipoff is language like, "unless the contract provides otherwise" or "absent an agreement to the contrary." (Legal Theory Lexicon 050: Default Rules and Completeness)

It would seem that if party wishes to be more sure that the currency of a contract should remain in euros, regardless of the lex monetae principle, it should include words which make clear, for example, that the currency of the contract will remain in euros regardless of whether the country of payment remains within the European Monetary Union or not. (Practical Law)

Express consent is clearly and unmistakably stated, rather than implied. It may be given in writing, by speech (orally), or non-verbally, e.g. by a clear gesture such as a nod. Non-written express consent not evidenced by witnesses or an audio or video recording may be disputed if a party denies that it was given. (Wikipedia)