United Kingdom - Passport & Nationality - British Overseas Citizen (BOC) - Descent from BOC Father
This solution relies on descent from a father who holds (or held) a valid British Overseas Citizenship (or BOC), and relies on a candidate's birth before 1 January 1983
Where the candidate has the Right of Abode*, then they would have been reclassified as a British citizen on 1 January 1983. Otherwise, the candidate became a British Overseas Citizen (or BOC) on 1 January 1983. Where the candidate holds no other nationality**, then it may be possible to upgrade this BOC status to full British nationality.
* The Right of Abode is normally gained:
- from a UK-born grandparent; OR
- where a woman married a British husband before 1 January 1983.
** Many countries do not allow Dual Nationality. So if the candidate already held this BOC status by descent, then they may not have become a citizen of their country of birth (even though they may hold a passport of that country).