 The second dollar (ZWN) was replaced on 1 August 2008 by the third dollar (ZWR), which was then phased out by the fourth dollar (ZWL) with short notice on 2 February 2009 because it rapidly lost value.The economic and trade sanctions imposed against the Zimbabwean government and the Reserve Bank made it difficult to incorporate modern security features on most banknotes issued since September 2008.The Reserve Bank originally planned to demonetise banknotes of the third dollar on 30 June 2009 but the Zimbabwean dollar as a whole has been suspended since 12 April 2009, implying that banknotes of both the third and fourth dollar are not de jure legal tender.