Geological mapping provides basic information on the geological structures and stratigraphy of an area. Maps are the usual form of representing geological data. Guidelines for data acquisition and evaluation, as well as for the preparation of the geological map (analog and digital), the legend, and the Explanatory Notes, have been prepared so that the geological maps will be uniform. These guidelines should help beginning geologists in the Geological Surveys, students, and geologists who are not employed by a Geological Survey to carry out their work in an efficient and targeted manner.