I also like to send it when I am lovelorn. This is a gadget that everyone made later.

You change the typing keyboard of your mobile phone to a 9-key one, and then type according to the number he sent, and the content will come out.

This later became the communication code between me and my best friend.

When you type it, it becomes pinyin. You can know what your friend probably sent by spelling it yourself.

I hope my answer is accepted ~ I want to upgrade ~ Lala Lala, thank you ~