Posts on British subject status may be found here.

British subject status is a class of British nationality associated with former British possessions outside the United Kingdom. British subjects derive that status from association with pre-1949 Ireland, or from being British subjects associated with either India or Pakistan who did not acquire the citizenship of that country following independence, or from being wives of (male) British subjects.

British subject status is a creation of statute and the core provision for it is found in Part IV of the British Nationality Act 1981. It does not automatically carry the right of abode in the United Kingdom, although there are some British subjects who have the right of abode in the UK. In addition to provision made by statue, there have been examples of persons treated as British subjects under what may be the Royal prerogative.

British subject status describes a legal attachment or bond for persons considered by the UK to be British nationals, albeit that unless such persons have acquired the right of abode in the United Kingdom, they may not live and work in the UK free of immigration controls by virtue of that status.

As a general rule, holders of British subject status are not considered to be UK nationals for the purposes of EU law and such persons do not hold the additional status of EU citizen. However, a small number of British subjects, who do have the right of abode in the United Kingdom, are considered to be UK nationals for the purposes of EU law and such persons hold the additional status of EU citizen and do have the right of free movement within the European Union.

British subject status has  limited modes of acquisition. Generally speaking it does not transmit (automatically or on application for naturalisation or registration) by birth in a territory or by descent, although there are exceptions made in respect of persons otherwise Stateless and in respect of minor children. There is no provision for naturalisation as a British subject.

British subject status also has modes of loss. For example it may be renounced, or it may lost through deprivation of citizenship on grounds of fraud or conduct. British subjects who derive that status from being British subjects associated with either India or Pakistan who did not acquire the citizenship of that country following independence, or from being wives of (male) British subjects, automatically lose that status upon acquiring any other citizenship or nationality.

Posts on British subject status may be found here.