How should a shipment of several parcels containing personal used items, be documented to ensure that the accepting customs is informed that this is intended as a tax exempt delivery of used personal items?

How does the post office assist the non professional sender to comply with this requirements?

I would like to ship my personal belongings from China to Namibia. May you please tell me if any of the items are not allowed:
1. clothes
2. Shoes
3. Books
4. Stationery: pens, pencils, books
5. Laptops
6. Cellphones
7. TVs
8. Cosmetics: perfume, lipstick, shampoo
9. Pots and pans

Since when concrete, China Post as mail transporter, decided to return to someone my personal belonging recorded in my personal name?
Is China Post aware that handling my personal belonging to someone else is treated by the Criminal Code as thief/pickpocket?
Has China Post the authority to handle someone's belonging recorded in it's personal name
to a street stranger?