For greater clarity, a “Chinese citizen” is a person of Chinese nationality under the Nationality Law of the People's Republic of China (CNL). Hong Kong residents who are of Chinese descent and were born in the Chinese territories (including Hong Kong), or persons who satisfy the criteria laid down in the CNL as having Chinese nationality, are Chinese nationals.

Source: http://www.gov.hk/en/residents/immig...ationality.htm

There is a whole section on HK residency entitlements and restrictions of British citizens in the HK Immigration Dept. web site:

http://www.immd.gov.hk/ehtml/topical_7.htm