Review of the history of the development of topographical keys in Serbian military cartography

The paper overviews several critical moments in developing symbology in Serbian military cartography. It covers the period up to World War I, from February 5th, 1876, when the Serbian military cartographic institution was called the Second (Geographical) Department of the Main General Staff of the Serbian Army; during World War I, including the 1917 "Thessaloniki" key; and the interwar period, when surveys of the Kingdom of Yugoslavia were conducted, maps of various scales were produced, primarily with a prime meridian passing through Paris, and the Military Geographical Institute was established. During the interwar period, the institute completed a survey of then-Yugoslavia and issued many maps. The paper then outlines the development of keys post-World War II, highlighting the changes in the political structure and the name of Yugoslavia and how the then-Military Geographical Institute recovered with significant effort and continued its work, incorporating technical advancements in the production of topographic maps. Notably, it details the production of several editions of the 1:25 000 topographic map as a key product. The application of aerial photogrammetry in surveys and map production and the advent of digital cartography and GIS technology in the early 21st century is emphasised. All these technological changes necessitated new knowledge and adjustments, which inevitably impacted the appearance and application of keys in Serbian military cartography.