A resident stamps a first day cover with a "Guangdong-Hong Kong-Macao Greater Bay Area" special stamp at Hong Kong General Post Office in south China's Hong Kong, Sept 26, 2019. 

Photo taken on Sept 26, 2019 shows the first day covers with the "Guangdong-Hong Kong-Macao Greater Bay Area" special stamp sheetlets at Hong Kong General Post Office in south China's Hong Kong. 

A staff member displays a postmarked first day cover with a "Guangdong-Hong Kong-Macao Greater Bay Area" special stamp at Hong Kong General Post Office in south China's Hong Kong, Sept 26, 2019. 

A resident prepares to post a first day cover with a "Guangdong-Hong Kong-Macao Greater Bay Area" special stamp at Hong Kong General Post Office in south China's Hong Kong, Sept 26, 2019. [Photos courtesy Xinhua]