1. Use the other party's name directly: If you know the other party's name, you can use it directly, such as "Mr. Zhang" and "Ms. Li".
2. Use the building number and room number: If you don't know the name of the other party, you can use the building number and room number, for example, "Residents in Building No.2 1202".
3. Use appellation: If the other person is an elder or you are familiar with the other person, you can use the corresponding appellation, such as "uncle" and "aunt".