Two passports, one citizenship

I have two passports, but only one citizenship-- so do many who lived under British colonial rule in Hong Kong. I am among the 350,000 British National Overseas (BNO) passport holders in the city, who have always treated the red booklet as just another travel document. It would be generous to call it a “second-class passport”: although its holders are entitled to a six-month visa-free stay in the U.K. and consular assistance, it is a long way from British citizenship.