ISO 3166-3:2013 Preview
Codes for the representation of names of countries and their subdivisions -- Part 3: Code for formerly used names of countries
The country codes from all three parts of ISO 3166 are available in .xml, .csv and .xls formats here: Country Codes Collection
ISO 3166-3:2013 provides principles and maintenance arrangements of a code for the representation of country names removed from editions 1 to 7 of ISO 3166 and the subsequent editions of ISO 3166-1.
Clauses 8 and 9 contain lists of all formerly used country names removed from ISO 3166 (now ISO 3166‑1) since 1974, together with the code element for each one of them.