I don’t know of a “Symbols” list. Here’s the Legend for what the different road colors mean. https://www.drivemodedashboard.com/topo-map-legend/
There’s a POI symbols menu in DMD that lets you choose to show/hide different types of POI on the map, that identifies what the symbol for each type looks like. Tap the Map Layers icon at the top of the Map screen. Next, In the left column scroll to/Tap POI Icon Highlight.
