Depending on the audit trail settings for the project in the Control Panel, you may be asked to provide a reason for the change. In the Control Panel, you also configure the reasons, and the possibility for users to provide their own reasons. The reasons offered for changes in a Custom Calculation file are the same ones as for changes in a method.
A preview in the Reason for changes window lists all entries that will be added to the audit trail. Check these entries before you provide a reason and confirm the changes.