.....between 01.01.1949 and 31.12.1982 were classified as aCitizen of the United Kingdom and Colonies (CUKC)and could hold a passport to that end.

The history of this CUKC appears below
TheUK Coloniesduring this period were:

*. Aden Colony (now part of Yemen) *. Akrotiri and Dhekelia Military bases in Cyprus *. Anguilla *. Antigua and Barbuda *. Ashanti (now part of Ghana) *. Bahamas *. Barbados *. Basutoland (now Lesotho) *. Bermuda *. British Antarctic Territory *. British Guiana (now Guyana) *. British Honduras (now Belize) *. British Indian Ocean Territory - Chagos *.
British Virgin Islands *. Cayman Islands *. Christmas Island (now part of Australia) *. Cocos and Keeling Islands (now part of Australia) *. Cyprus *. Dominca *. Falkland Islands *. Fiji *. Gambia Colony (now part of Gambia) *. Gibralter *. Gilbert Islands (now part of Kiribati) *. Kiribati *. Gold Coast Colony (now part of Ghana) *. Grenada *. Guyana *. Hong Kong *. Jamaica *. Kenya Colony (now part of Kenya) *. Kowloon (now part of Hong Kong) *. Kuria Muria Islands (now part of Yemen) *. Line Islands (now part of Kiribati) *. Malta *. Mauritius *. Montserrat *. New Territories (now part of Hong Kong) *. Nigerian Colony (now part of Nigeria) *. North Borneo and Labuan (now part of Malaysia) *. Penang and Malacca (now part of Malaysia) *. Perim Islands (now part of Yemen) *. Phoenix Islands (now part of Kiribati) *. Pitcairn Islands *. Rotuma (now part of Fiji) *. Sarawak (now part of Malaysia) *. Seychelles *. Sierra Leone Colony (now part of Sierra Leone) *. Singapore *. South Georgia and South Sandwich Islands *. St Christopher, St Kitts and Nevis *. St Helena, Ascension, Gough and Tristan da Cunha *. St Lucia *. St Vincent and the Grenadines *. Trinidad and Tobago *. Turks and Caicos *. Tuvalu

The Heads of Commonwealth Government decided in 1948 to embark on a major change in the law of nationality throughout the Commonwealth, following Canada's decision to enact its own citizenship law in 1946.
Until then, all Commonwealth countries, with the exception of the Irish Free State, had a single nationality status: British subjectstatus.
It was decided at that conference that the United Kingdom and the self-governing dominions would each adopt separate national citizenships, but retain the common status of British subject.
Thus the British Nationality Act 1948 provided for a new status ofCitizen of the United Kingdom and Colonies(CUKC),consisting of all those British subjects who had a close relationship (either through birth or descent) with the United Kingdom and its remaining colonies.
Each other Commonwealth country did likewise, and also established its own citizenship (with the exception of Newfoundland which became part of Canada on 1 April 1949, Newfoundlanders hence becoming Canadian citizens).
The Act also provided that British subjects could be known by the alternative titleCommonwealth citizen.
Source: whatpassport