“The term 'Australian nationality' entered usage only in the 1940s when the Commonwealth's full sovereignty was realised, but during the 1960s the census continued to require Australian citizens to declare their nationality as British. Calwell talked of Australian nationality in the 1940s, and policymakers in the mid-1950s recognised that, at least in law, Australian citizens could be described as being of Australian nationality, but the term was given no official recognition or meaning and Australian citizens were considered to be of British nationality.*
Not until 1969 did they cease to
be British subjects, and retain only the
status of British subjects; a semantic change that attracted much general criticism for being confusing and also criticism from the Labor opposition, which regarded the concept 'British subject' as an anachronism in need of abolition. Only then were Australian citizens to be described as such for official purposes rather than as British subjects, and the Nationality and Citizenship Act was renamed the Citizenship Act. The Act was renamed again in 1973: the Australian Citizenship Act”
Citizenship in Australia - Citizenship in Australia: A Guide to Commonwealth Government Records
*
Memorandum, THE Heyes, Secretary of the Department of Immigration to Minister for Immigration, July 1954, NAA: A432, 1961/3191
The concept of Australian citizenship vs British subject can be very confusing and In my professional life I keep coming across Brits who have been here since the 50’s and 60’s and never left
Mods, sorry about going off topic