56.The main purpose of Part 2 of the Act is to make provision regarding the parliamentary scrutiny of “devolved subordinate legislation”. That expression is defined in section 37 of the Act to mean subordinate legislation contained in a Scottish statutory instrument (“SSI”), excluding special procedure orders (which are dealt with in Part 4 of the Act). Part 2 replaces the provisions of the Scotland Act (Transitory and Transitional Provisions) (Statutory Instruments) Order 1999 (S.I. 1999/1096) (“the SI Order”). That Order was largely based on the provisions of the Statutory Instruments Act 1946 (c.36) (“the 1946 Act”) which applies to statutory instruments (“SIs”).