02 voice mail

You're referring to the classic "02" voice mail greeting!

For those who may not know, "02" is a common voice mail greeting in many countries, particularly in the UK and other parts of Europe. When you call someone and they don't answer, you might hear a recorded message saying:

"Hello, I'm not available to take your call right now. Please leave a message after the tone, and I'll get back to you as soon as possible. Beep."

The "02" refers to the tone that follows the greeting, which is a beep or a series of beeps that indicate when it's time to leave your message.