Currently, a Legend offers incredible control over what and how information is summarized. Any column can be turned on or off as needed, and markups that share the same data in the second column will be added together.
However, there is a deeply unintuitive aspect to Legends: the Symbol column cannot be turned off. The best workaround is setting the symbol scale to 1%, which shrinks it down to a nearly unnoticeable dot. It is odd to me that every column except one can be controlled, especially because it makes it difficult to count polylines as different line items. For example, if two polylines have nearly identical data in their columns, but are different colors, the legend will always break them into two line items. If I wanted to separate them by color, I would enable the Color column in the legend.
As currently implemented, Legends suffer from a hole in their flexibility that is extremely limiting under specific circumstances.
