And that's all before we start to consider sub-groups, mixed-race, and all the other issues around racial categorisation.

BBC: Race bias in cancer 'costing lives'

According to the ONS many public sector organisations fall outside of this categorisation.

BBC: Public sector salaries: methodology

Virginia Dejani, the Academy's executive director, said he was made an honorary member because "what he has accomplished defies categorisation".

BBC: Bob Dylan made honorary member of US Arts Academy

In another country you could flee easy categorisation by your education, your work, your class, your family, your accent, your politics.

ECONOMIST: Being foreign

It is not just the shops and museums that defy categorisation.

BBC: The stranger side of Switzerland

Sir Mark says genome science has also led to improvements in the diagnosis and categorisation of inherited diseases and treatments for inherited forms of diabetes, based on a patient's genetic makeup.

BBC: The man who gives away ?600m a year

It is his defiance of categorisation.

ECONOMIST: Vernon Jordan, gliding through