According to a 13 June 2018 press release, on 18 July 2018 the South African Reserve Bank planned to introduce new banknotes to commemorate the 100th anniversary of the birth of Nelson Mandela, known as Madiba. The commemorative notes have the same front as the existing issues, but with a young Madiba on back. They will circulate in parallel with the exiting issues.
Courtesy of Richard Miranda, Claudio Marana, Craig Eustace, Hermann Huber, Antje Bird, and Chris Huff.