1. Swiss Law requires for an arbitration agreement to be valid, that it is made in writing. The written form has as a purpose firstly to warn the parties about the existence of an arbitration clause and secondly to serve as evidence. When reference is made to an external document, and particularly when this reference is of a global nature only (not specifically mentioning the arbitration clause) the question as to whether the requirements of form are met, must be decided upon the principle of trust.