The new computer-based registration system, a project of the National Museum of Geology and Mineralogy in the Netherlands, will considerably increase the accessibility of the Museum collection. This greater access is realized by computerisation of the data in great detail, so that an almost unlimited number of operations to select and sort the data is possible. A flexible design of annotating information, mainly in plain words, saves considerable time. The fast mechanical data processing permits the efficient preparation of catalogues which contain selected information about the geological collection; as an additional benefit labels may be produced at low costs. The RGM system disposes of the burden of classical registration books and card-indexes, without any essential quality being lost. It combines a minimum of man-hours with an optimal flexibility in storage and retrieval of data, and an acceptable employment of computer time and equipment. The system may also serve for the registration of collections of other institutions, in geology as well as zoology and botany.