You would have become a British protected person on 1 January 1983 if you were a Brunei citizen, or had already been a British protected person, or were a child of any of the mentioned categories.
You would have lost your British protected person status if:
The territory where you lived became independent, and you became a citizen of that country.
You became a citizen of another country.
A British protected person can get a British passport, just as a British subject or a British Overseas Territories citizen. However, naturalisation is required to get the same rights as a British national.