set nobody 係唔夠的
只要對方phone book 入面有足夠多電話號碼而其中有一個係你個號碼
Q: Who can see my phone number?
On Telegram, you can send messages in private chats and groups without making your phone number visible. By default, your number is only visible to people who you've added to your address book as contacts. You can further modify this in Settings > Privacy and Security > Phone Number.
Note that people will always see your number if they know it already and saved it in their address book.
而且當你轉電話號碼仲會自動再加入對方phone book 同link up
Q: How do I change my phone number?
You can change your number in Telegram and keep everything, including all your contacts, messages, and media from the Telegram cloud, as well as all your Secret Chats on all devices.
Important: Your mutual contacts (people in your contacts who also have your number) will get your new number added to your contact in their address book unless you have blocked them in Telegram. This makes changing numbers even easier.
另外peer to peer Voice call 要set 做my contact 或者nobody