The Span Columns checkbox indicates that the Line’s description field text should use the entire width of all columns in the report.
Justification and formatting for the description will occur across the whole report. When the “Span Columns” field is unchecked, the description will be formatted and justified within the bounds of the description column on the report.
Note: If the Formatting Fields checkbox is not checked on the context ribbon, this field will not appear in the Line Definition workspace.