How do I turn on PM in Facebook?

Related questions

1. What is an example of preventive maintenance?
2. What is PM Facebook?
3. What is the difference between DM and PM?
4. How do I see private messages on Facebook?
5. Why is it 12pm and not 12am?
6. What is PM and AM stand for?
7. What is DM slang?
8. What does SKL and SML means?
9. What are the classification of maintenance?
10. How many types of maintenance are there?

Tags

1. #check
2. #messages
3. #click
4. #allow
5. #uncheck
6. #contact
7. #settings
8. #showing
9. #button
10. #general
11. #privately
12. #changes
13. #message
14. #people