China Post - Hongkong Post Joint Issue on 20th Anniversary of the Return of Hong Kong to China (Hong Kong 2017)

Stamp China Post - Hongkong Post Joint Issue on 20th Anniversary of the Return of Hong Kong to China it reflects the thematic directions:

A flag is a piece of fabric (most often rectangular or quadrilateral) with a distinctive design that is used as a symbol, as a signaling device, or as decoration. The term flag is also used to refer to the graphic design employed, and flags have since evolved into a general tool for rudimentary signalling and identification, especially in environments where communication is similarly challenging (such as the maritime environment where semaphore is used). National flags are patriotic symbols with varied wide-ranging interpretations, often including strong military associations due to their original and ongoing military uses. Flags are also used in messaging, advertising, or for other decorative purposes. The study of flags is known as vexillology, from the Latin word vexillum, meaning flag or banner.

A people's history, or history from below, is a type of historical narrative which attempts to account for historical events from the perspective of common people rather than leaders. There is an emphasis on disenfranchised, the oppressed, the poor, the nonconformists, and otherwise marginal groups. The authors typically have a Marxist model in mind, as in the approach of the History Workshop movement in Britain in the 1960s.

History (derived from Ancient Greek ἱστορία (historía) 'inquiry; knowledge acquired by investigation') is the systematic study and documentation of the human past