You've missed the footnote next to the word "Britain": >Usage is mixed. The Guardian and Telegraph use Britain as a synonym for the United Kingdom. Some prefer

You've missed the footnote next to the word "Britain": >Usage is mixed. The Guardian and Telegraph use Britain as a synonym for the United Kingdom. Some prefer to use Britain as shorthand for Great Britain. The British Cabinet Office's Government Digital Service style guide for use on gov.uk recommends: "Use UK and United Kingdom in preference to Britain and British (UK business, UK foreign policy, ambassador and high commissioner). But British embassy, not UK embassy."