A man shows his passbook. source
In South Africa, pass laws were a form of internal passport system designed to segregate the population, severely limit the movements of the black African populace, manage urbanisation, and allocate migrant labour. The black population was required to carry these pass books with them when outside their homelands or designated areas. Passes were opposed by groups like the revolutionary syndicalists and the black nationalists. Before the 1950s, this legislation largely applied to African men, and attempts to apply it to women in the 1910s and 1950s were met with significant protests. Pass laws would be one of the dominant features of the country’s apartheid system, until effectively ended in 1986.
Source: Pass Laws