Any delegated legislation (not including subdelegated legislation) to which the Statutory Instruments Act 1946 applies. This includes both (1) delegation made under powers conferred by an Act passed after 1947, either on the Crown or on a government minister, and expressed by that Act to be exercisable by Order in Council in the former case or by statutory instrument in the latter; and (2) delegation made under powers conferred by pre-1947 legislation.
The 1946 Act requires statutory instruments to be numbered, printed, and published by the Queen's printer. They are numbered consecutively for each calendar year in the order in which the printer receives them; for example, the first statutory instrument to be received in 1993 would be cited as “S.I. 1993 No. 1”. Moreover, as a modification of the rule ignorantia juris non excusat (ignorance of the law is no excuse), the Act makes nonpublication a defence to proceedings for contravening a statutory instrument unless other adequate steps had been taken to bring it to the public notice. The Act is also concerned with certain aspects of parliamentary control. It standardizes negative resolution procedure for statutory instruments by providing that, if the enabling statute simply makes them subject to annulment by resolution of either House of Parliament, they are to be laid before Parliament for 40 days and liable to annulment during that period. It further provides that any statutory instrument required to be laid (either because of that rule or because the enabling statute expressly says so) must be laid before becoming operative unless there is good reason to the contrary (in which case, an explanation must be given to the Lord Chancellor and the Speaker). See also Joint Committee on Statutory Instruments.