The main objective of this book is to examine the mechanisms of two main tools serving to determine the content of international commercial contracts, namely interpretation and gap filling. It essentially focuses on a comparative analysis of the rules provided by four main – uniform and harmonized – sets of rules conceived according to the needs of international trade. While doing so, it discusses various important theoretical aspects of contract interpretation in general and refers to different interpretation approaches which are traditionally used in different law systems by also taking into account the specific context of international commercial contracts. Accordingly, it treats not only the practical solutions to be extracted from harmonized instruments but also theoretical perspectives which could help clarify the content of the rules provided by these instruments.

To start with, contract interpretation can be briefly described as the understanding of the language (or the meaning) of a contract and of rights and obligations that are created by it. It is a topic which has long been treated by lawyers and scholars coming from all different legal systems. Yet it seems that the thousands of pages which have been written so far fall short to settle questions and controversies related to it.

This seems to be mainly because “language” which serves as the most important tool both to conclude and to interpret the contract is far from being a static and easy-to-deal-with tool, as it changes from one context to another. That explains why approaches which consider language as a common tool to be used in the same manner by its all competent users cannot answer the question why there are so many differences of opinion when it comes to ascertaining the meaning of an actual text. This is, indeed, a phenomenon that we all can observe in our lives and that is also confirmed by research.

With a more focused analysis, it can be seen that contractual interpretation cannot be fully explained without reference to different types of context and is not just a topic to be addressed with dictionaries.