Undefined metadata values on a tree
When visualizing a metadata category where one or more nodes in the tree have undefined values, these nodes will be visualized using a default value. This value will always be shown in italics in the top of the legend (see the entry "Unknown" in figure 20.27). To remove this entry in the legend, all nodes must have a value assigned in the corresponding metadata category.
Figure 20.27: A legend for a metadata category where one or more values are undefined. Fill your metadata table with a value of your choice to edit the mention of "unknown" in the legend.