To #341:
1. British National (Overseas) (BN(O)) and British Overseas Citizen (BOC) are two separate classes of (quasi-)British nationalities. They are not synonymous.
2. Ethnic Chinese resident in HK and born in China (including HK, either before or after the handover) have always been regarded, either before or after the handover, as Chinese nationals by mainland China. The UK acknowledges this position. Hence most HK Chinese were not people who "had no other nationality or citizenship on 30 June 1997."
3. All people with the BN(O) status applied for and received their first BN(O) passports before the handover or right thereafter (for people born very close to the handover) (or were listed as minor children in their BN(O) parents' BN(O) passports). It is not possible to apply for the first BN(O) passport after the handover (save for the exception mentioned above). If someone's name has never appeared in a BN(O) passport, s/he does not have the BN(O) status. Period. Once acquired the status is valid for life unless renounced, even though the BN(O) passport may be allowed to expire and not renewed.