United Kingdom - Passport & Nationality - British Citizenship by Descent (UKM Registration through Marriage)
1) who was born between 01.01.1949 and 31.12.1982;
2) whose parents were married before 31.12-1982;
3) whose mother was registered as a British citizen before 31.12.1982 based on her marriage to a British citizen; AND
4) who was born after the mother's registration as a British citizen;
... can register as a British citizen.