Statutory instrument
Title of the statutory instrument and year. Abbreviation SI year/number. Place of publication: Publisher.
Example:
The Bathing Water Regulations 2013. SI 2013/1675. London: The Stationery Office.
Online statutory instrument
If you are referencing a statutory instrument you found online, this should be indicated in the reference.
Title of the statutory instrument and year. Abbreviation SI year/number. [Online]. Place of publication: Publisher. [Date accessed]. Available from: URL
Example:
The Export Control (Amendment) Order 2018. SI 2018/165. [Online]. London: The Stationery Office. [Accessed 15 May 2018]. Available from: http://www.legislation.gov.uk/