noun
contact network; phone tree; contact list
A system or list of contact information for members of an organization, often used for emergency notifications or group communication. Commonly used in schools, workplaces, and community groups.
学校の連絡網で、明日の休校が知らされた。
Tomorrow's school closure was announced through the school's phone tree.
緊急時
Let's update the contact network in preparation for emergencies.