Division 5 of the CIE deals with the subject of “Exterior and other Lighting Applications” and has since 1991 had a Technical Committee (TC5.12) working on a “Guide on the limitation of the effects of obtrusive light from outdoor lighting installations”. This Committee did much of its work under the chairmanship of Dr. Alec Fisher of Australia, who has now retired and passed on the work to the current author. The present report outlines the content of the proposed Guide and details its relevance to help preserve the astronomical sky. It also highlights the close links with CIE Committee TC4.21, which works directly on the problems of sky glow.