A couple of years ago the Ordnance Survey posted a series of cartographic design principles to inform and promote “good map design.” The principles are understanding user requirements, a consideration of the display format (e.g., paper vs. web), simplicity, legibility, consistency, accessibility (everything from data format to colourblind inclusiveness to licensing), a clear visual hierarchy, and good composition. (Last year the Ordnance Survey’s blog published a series of posts on these principles, using mostly similar text but different examples.)