保留必须以书面形式告知缔约国、缔约组织以及有权成为条约缔约方的其他国家和国际组织。如果一现行条约是一国际组织的组成文书，或是据以设立一有权接受保留之机关的条约，则对此条约的保留也必须告知该组织或机关。
A reservation must be communicated in writing to the contracting States and contracting organizations and other States and international organizations entitled to become parties to the treaty.