ISO 11760:2005 describes a simple classification system for coals providing guidance on the selection of the appropriate ISO standard procedures for the analyses and testing, international comparison in terms of some key characteristics and descriptive categorization of coals. The system is applicable to coals of all ranks, but care is required in relation to the classification of some types of coal. It is also applicable to a wide range of representative coal samples, provided their exact nature is stated. Such samples include bore-core seam sections and composite samples, raw (as-mined) coal, washed coal, blends of coals of similar rank and selected, specified size fractions.