United Kingdom
Statutory Instruments are the principal form in which delegated or secondary legislation is made in Great Britain. The process of creating of Statutory Instruments is governed by the Statutory Instruments Act 1946. This Act replaced the previous system in which Statutory Rules and Orders were made under the Rules Publication Act 1893. The change took place in 1948.
The advent of devolution to Scotland and Wales in 1999 resulted in many powers to make Statutory Instruments being transferred to the Scottish Government and Welsh Assembly Government respectively. Instruments made by the Scottish Government are now classed separately as Scottish Statutory Instruments.
 Republic of Ireland
In the Republic of Ireland the term "Statutory Instrument" is given a much broader meaning than under the UK legislation. Under the Statutory Instruments Act 1947 Statutory Instruments are defined as being "an order, regulation, rule, scheme or bye-law made in exercise of a power conferred by statute."
However only certain Statutory Instrument are published and numbered by the Stationery Office, this being mostly where the statute enabling the enactment of delegated legislation required that any such legislation be laid before the Houses of the Oireachtas.
 Other countries
Canada uses statutory instruments for proclamations by the Queen of Canada. For example, the Proclamation of the Queen of Canada on April 17, 1982 brought into force the Constitution Act 1982, the UK parts of which are known as the Canada Act 1982.
- Statutory Instruments Act 1946, section 1
- Rule Making by Commonwealth agencies- June 30, 2009
- Consolidated Index of Statutory Instruments- March 31, 2011
- Republic of Ireland: