Extracts from UNIDROIT PRINCIPLES OF INTERNATIONAL COMMERCIAL CONTRACTS 2016

“ARTICLE 1.1 (Freedom of contract)

The parties are free to enter into a contract and to determine its content”

“ARTICLE 2.1.1 (Manner of formation)

A contract may be concluded either by the acceptance of an offer or by conduct of the parties that is sufficient to show agreement.

ARTICLE 2.1.2 (Definition of offer)

A proposal for concluding a contract constitutes an offer if it is sufficiently definite and indicates the intention of the offeror to be bound in case of acceptance.”