Constants on a report provide a method for developers to create Key / Value pairs for a report. The Constants Editor shows the Key / Value pairs for the report and is where the values can be edited. Note that constants are stored in the report file, and the values rendered will be those in the report file.
Click the "Add" button at the bottom of the list to add a new Key / Value pair to the list. To delete an existing Key / Value pair select the line from the list and use click "Remove".
Pressing OK will save the changes made, likewise the Cancel button will discard any changes to the constants.