On February 4, Central Bank of Sri Lanka will issue a Rs 1000 banknote to commemorate 70th Anniversary of Independence. 5 million banknotes will be issued and the serial numbers of the notes will be from S70/1 000001 – S70/5 1000000.
Press release by the bank is here (http://www.cbsl.gov.lk/pics_n_docs/02_prs/_docs/press/press_20180130ev.pdf).
Aditya