Hello, if you don't want the number of important members such as the boss to show to other employees, the administrator can set the number to hide to the members:
[Desktop client]: Administrator login to the Admin Panel (oa.dingtalk.com)-[ Contacts]-Click on the corresponding employee-[Customize Mobile Display Information] to edit;
[Mobile app]: Administrator go to DingTalk mobile APP, click [Contact]-[Organization Management]-[Company Contacts]-[Manage [Employee & Department] - [Edit Staff Information] - [Hide mobile number];
If you want all employees' numbers not to be displayed on the phone:
Admin can log in to the Admin Panel - [Settings] - [Contacts] - [Profile Information Fields], do not check the phone number.

Mobile phone number to view the unified settings of all staff: Administrator in [DingTalk mobile app] - [Contacts] - [Organization Management] - [Security Center] - [Phone Number Display Settings].
[Public mode]: The mobile phone number is displayed publicly;
[Private mode]: All mobile phone numbers are not displayed;
[Hidden Mode]: The mobile phone number hides the middle 5 digits. Click to view the complete number. If you view more than a certain number of colleague mobile phone numbers, they will be reported as risk to the administrator.

Tips: Employees can't set their own numbers to hide, but when adding friends, you can choose whether to share your number with each other.