I'm at the unique values symbology and want to add one single value to the symbology scheme. Other than fire up ArcMap, I can't figure out how to do this. Pro's Unique values window is a bit baffling.
can you click the "+" sign
then the list of values will be generated and you can select what ever you want.
It also allows you to add values not present in the layer, in case you're setting up a layer for future additions. Very handy!