<Li> The use of internal passport to restrict residency and movement in the Soviet Union and in Apartheid South Africa had the effect of tying local "citizens" to their assigned administrative entity (titular nations and bantustans, respectively). </Li> <Li> Following the federalization of Czechoslovakia in 1968, Czechoslovak citizens also possessed an internal citizenship of either the Czech or Slovak Republic . Upon the nation's peaceful dissolution in 1993, this was used to determine whether they ought to receive Czech or Slovak citizenship . </Li> <Li> Before the break - up of Yugoslavia in 1991, Yugoslav citizens possessed an internal citizenship of their own republic (Serbia, Croatia, Bosnia and Herzegovina, Slovenia, Macedonia, Montenegro) as well as Yugoslav citizenship . In Serbia and Montenegro, this system was in effect until 2006 . </Li> <Li> When Singapore joined Malaysia in 1963, all Singapore citizens were granted Malaysian citizenship . Singapore citizenship continued to exist as a subnational citizenship, and continued to be legislated by the Legislative Assembly of Singapore subject to the approval of the Parliament of Malaysia . Upon Singapore's independence from Malaysia in 1965, Malaysian citizenship was withdrawn from Singapore citizens, and all Singapore citizens became citizens of the new Republic of Singapore . </Li>

Can a us citizen have more than 2 citizenships