You can download the 5th Edition of the Guidelines for best practice in the use of the Assessment Centre Method in South Africa (as approved at the 2015 ACSG conference) from the link above. A South African task force reviewed this document against the 2007 South African Guidelines. The 5th edition was endorsed at the 36th Annual ACSG conference held in Somerset West, South Africa during March 2015.
The 6th Edition of the (American) Guidelines and Ethical Considerations for Assessment Center Operations was endorsed during the 38th International Congress on Assessment Center Methods held during October 2014 in Alexandria, Virginia, USA. These Guidelines will be published in the January 2015 edition of the Journal of Management