National resource assessments are intended to give some insight into future possibilities for the recovery of a desired resource. The resource numbers themselves only useful when related to economically controlled factors, such as industry capability as reflected in rated of production, rates of discovery, and technology development. To that end, it is useful to divide the resource base into component parts to which appropriate econometrics can be applied. A system of resource reporting adhering to these principles has been agreed to by the two major resource agencies in Government, the U>S. Geological Survey and the U.S. Bureau of Mines (USGS Bulletin 1450-A). Conceptually, then, a plan for resource reporting has been devised, and all resource reporting by these two agencies follows the agreed-upon pattern. Though conceptual agreement has been reached, each commodity has its own peculiar data problems; hence an operational definition to fit the conceptual pattern must be evolved for each mineral. Coal is the only commodity to date for which an operational agreement has been reached (USGS Bulletin 1450-B), but the basic essentials of an operational classification within the guideline of Bulletin 1450-A have been reported for oil and gas in USGS circular 725. The basic classification system is now well established and received general endorsement by Resources for the Future in a study of mineral resource classification systems prepared for the the Electric Power Research Institute (Schanz, 1976), and with respect to coal by the International Energy Agency.