United Kingdom - Passport & Nationality - British Citizenship by Birth (Post 82 - Parent with RoA)
A claim for British Citizenship by birth applies where:
1) the candidate was born in the UK after 31 December1982; AND
2) a parent was considered "Settled" at the time of your birth.
This "Settled" status includes both British and Irish citizens, a person who held the Right of Abode or Permanent Residency in the UK. If this was the case, you were born British.
A parent has the Right of Abode where they were a Commonwealth citizen and one of their parents was born in the UK before 1983.