What does the Guangdong, Hong Kong and Macao customs clearance form mean?

Customs clearance certificate: If you need to enter and leave the Guangdong-Hong Kong-Macao port, you should use the "Guangdong-Hong Kong-Macao Customs Clearance" function of "Guangdong-Macao Code" in advance, choose "Guangdong → Macao" or "Macao → Guangdong" according to the direction of entry and exit, declare your health according to the prompts, check your personal information, obtain the customs clearance certificate of Guangdong-Hong Kong code, and pass the customs with the customs clearance certificate of Guangdong-Hong Kong code. Hong Kong residents who meet the "Easy Return to Hong Kong" plan should go through the "Guangdong-Hong Kong-Macao Customs Clearance" function of "Guangdong-Hong Kong Code" in advance before arriving at the designated port, select "Guangdong → Hong Kong", complete the health declaration according to the prompts, obtain the customs clearance certificate of Guangdong-Hong Kong Code, select "Enter Hong Kong Health Declaration Form", and transcode to generate the green code clearance of Hong Kong health declaration form.