Dynamic data callout
In my data graph, we need a way to click on a data point and insert a data callout. This is similar to what you can do in an excel line graph, but it would need to be dynamic meaning as you input more data, the callout follows the data point.
Rachel Lien commented
This would be ideal for calling out business events that have been identified previously so we don't have to review them and try to remember the root cause each time...
ie "the sales dropped $20M on the point associated with October 2018 because of a rebate promotion".