> But in general, outside clearly defined exceptions, contracts and declarations do not have a form requirement, so even oral agreement or "conclusive behaviour

> But in general, outside clearly defined exceptions, contracts and declarations do not have a form requirement, so even oral agreement or "conclusive behaviour" (sign language, point-and-grunt, silently carrying an item to the cash register) are absolutely valid. Correct in the US, although it's worth mentioning the Statute of Frauds and the Uniform Commercial Code: https://en.wikipedia.org/wiki/Statute_of_frauds https://en.wikipedia.org/wiki/Statute_of_frauds https://en.wikipedia.org/wiki/Uniform_Commercial_Code https://en.wikipedia.org/wiki/Uniform_Commercial_Code