The Personal Data Protection Board (" Board"), in its Principle Decision dated 22.12.2020 and numbered 2020/966 (" Principle Decision"), envisaged that the data controllers should establish mechanisms enabling them to confirm the contact information of the data subjects in order to prevent the personal data of the data subjects from being sent to third parties through communication channels such as mobile phone or e-mail, as contrary to Articles 4 and 12 of the Personal Data Protection Law numbered 6698 (" PDP Law"). The Board determined that the data controllers who operate in the sectors such as e-commerce, telecommunication, transportation, and tourism, in order to provide documents containing personal data