The objective of this leaflet is to supplement the information in UIC Leaflet 712 by giving recommendations regarding the maintenance of rails (monitoring and elimination of defects). The document contains three chapters: Chapter 1: Key inspection factors Chapter 2: Defect classification and action to be taken Chapter 3: Detection methods. and three Appendices Examples of research results on crack growth rates Defect management Qualification of operators and approval of inspection equipment. This document takes account of recent experience acquired by railways on the how these problems develop and the measures to be applied to rail defects caused by contact rolling fatigue which is an increasingly common phenomenon. This document is limited to describing the principles of monitoring and eliminating rail defects which may result in rail cracks and breakages.