Statutory instrument (UK)  A statutory instrument (SI) is the principal form in which delegated legislation is made in Great Britain. Statutory instruments are governed by the Statutory Instruments Act 1946. They replaced statutory rules and orders, made under the Rules Publication Act 1893, in 1948. Most delegated legislation in Great Britain is made in the form of a statutory instrument. (In Northern Ireland, delegated legislation is organised into statutory rules, rather than statutory instruments.) The advent of devolution in 1999 resulted in many powers to make statutory instruments being transferred to the Scottish and Welsh governments, and oversight to the Scottish Parliament and National Assembly for Wales. Instruments made by the Scottish Government are now classed separately as Scottish statutory instruments. A statutory instrument is used when an Act of Parliament passed after 1947 confers a power to make, confirm or approve delegated legislation on:  "Minister of the Crown" includes the Welsh Ministers and various Acts provide that delegated legislation, although made by another person (for example, the General Dental Council), is also to be made by statutory instrument. Often the Minister authorised to issue a statutory instrument is "the Secretary of State", which the Interpretation Act 1978 defines as "one of Her Majesty's Principal Secretaries of State"; this form effectively allows the Prime Minister to create new departments and define or redefine their responsibilities at will. A statutory instrument is also used when the Queen in Council or a Minister exercises a power under an Act passed before 1947 which is legislative, rather than executive, in character. Use of a statutory instrument is not required where the parent Act does not specify it. This may be the case where delegated legislation is of only limited application and therefore not of general importance. Instead, other provisions may be made for publishing the legislation. So, for example, an Order providing for the transfer of contracts from one National Health Service body to another may only be notified to the affected bodies, and by-laws made by a local council may be publicised through an announcement in local newspapers. The main effect of delegated legislation being made by statutory instrument is that it is effective as soon as it is made, numbered, catalogued, printed, made available for sale and published on the internet. This ensures that the public has easy access to the new laws. Numbers are assigned by Her Majesty's Stationery Office and are sequential within the year of making. The number provides a means of citing the statutory instrument in addition to the title given by the instrument itself. So, for example, The Income Tax (Exemption of Minor Benefits) (Amendment) Regulations 2003 are numbered and may be cited as SI 2003 No. 1434 or SI 2003/1434.