Use a legend or key to explain what your icons or colors represent. If you maintain consistency, people will learn to read your diagrams quickly and with purpose.
Spend some time creating a good legend that you can simply drop from one diagram to another. It doesn’t need to be complicated and be sure to keep it small enough to slip into empty space on your map. If you invest some time from the start, you won’t have to keep reinventing the wheel.
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