Since we love map making for its clarity, Wikipedians developed several local cartographic styles over the years.
Summary tables of each major map convention used in Wikipedia, across all languages. While the conventions are strongly recommended, cartographers are free to fit their specific needs. Each convention has its own sub-page, containing:
An introduction explaining the style objectives and the most convenient way to create a such map.
A color summary table with two (up-to-date) map examples.
The naming convention for upload, and other advice like the scale or the legend.
An up-to-date SVG template.
Further details on history, limits, and possible expansions.
A gallery of examples.
The image renaming tool working on Commons (request this tool · renaming guidelines), and for admins, the naming conventions can be used to harmonize image names and map names.