When creating a custom report you can select optional tables. If an optional table has no data for any records returned by the report, the table's selected columns are shown with no values. For example, if Direct Appraiser - User ID is selected as a column to show in a report that returns a list of learners, but you want to include learners who do not have a direct appraiser, you would select the Direct Appraiser table as optional.
By default, all tables are selected as optional.
To select optional tables
Additional Information
Select Custom Report Grouping Information
Select Custom Report Column Order
Select Custom Report Column Filters
Select Custom Report Columns to Sort on (Advanced)