Include contextual information if this is appropriate and will not distract from, or obscure, the data. Examples of supporting information are mean, target, baseline, deviation, regression, best-fit or trend lines, confidence intervals, acceptable ranges, and comparison with a previous time period.

When needed, the legend should be placed in a prominent area, such as the bottom left corner of the graph, listing the items in the same sequence as they occur in the graph. It may be more effective to label the data directly (eg by adding labels to each line at the right-hand side of a line graph), provided that the data items are distinct enough. This eliminates the extra time it would take a reader to understand a legend.