ZDNET – This is one of the codes referenced in the article.

• 67 Hide Caller ID for one call (iPhone and Android). In the US, dialing *67 before a phone number hides your caller ID for that one call, making “Private Number” appear on the recipient’s screen, which is useful when calling businesses or people you don’t know well. Outside the US, the equivalent code is *31#, so it works the same way in regions where *67 isn’t supported. Tip: If your caller ID is normally hidden but you want it to appear just once, dial *82 before the number to temporarily unblock it.