ISO/TS 28923:2007 gives safety requirements, and the means of verifying them, for the design and construction of guards, only able to be opened using a tool, which are used to guard the moving parts of the power transmission of self-propelled ride-on machines and mounted, semi-mounted or trailed machines used in agriculture. In addition, it specifies the type of information on safe working practices (including residual risks) to be provided by the manufacturer. It deals with the significant hazards, hazardous situations and events relevant to guards of moving parts of power transmission used as intended and under the conditions foreseen by the manufacturer.