When visualizing a metadata category where one or more nodes in the tree have undefined values (empty fields in the table), these nodes will be visualized using a default value in italics in the top of the legend (see the entry "Unknown" in figure 22.27). To remove this entry in the legend, all nodes must have a value assigned in the corresponding metadata category.
Figure 22.27: 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. Note that the "Unknown" that is not in italics is used for data that had a value written as "Unknown" in the metadata table.