In October 1945, the Rules of the Air and Air Traffic Control (RAC) Division at its first session made recommendations for Standards, Practices and Procedures for Air Traffic Control. These were reviewed by the then Air Navigation Committee and approved by the Council on 25 February 1946.
Excerpt from the document:
This edition incorporates all amendments adopted by the Council prior to 24 February 2005 and supersedes, on 24 November 2005, all previous editions of Annex 2.
The RAC Division, at its second session in December 1946 – January 1947, reviewed Doc 2010 and proposed Standards and Recommended Practices for the Rules of the Air. These were adopted by the Council as Standards and Recommended Practices relating to Rules of the Air on 15 April 1948, pursuant to Article 37 of the Convention on International Civil Aviation (Chicago, 1944) and designated as Annex 2 to the Convention with the title International Standards and Recommended Practices — Rules of the Air. They became effective on 15 September 1948
To continue reading see the pdf below: