The In Reference To header is being shown due to a selection on your invoice template or a selection on the invoice itself. When enabled, you will see this header and you will see your line items grouped by project/case/matter on your invoice(s).
Disabling/deselecting will remove that header and will organize your line items by labor and expenses overall, and not organize by project/case/matter.
Disabling this setting can be found in two possible areas:
- Via the invoice template and uncheck the Group by Project checkbox.
- Via the Invoice Details tab for this particular invoice and uncheck the Group Details by Project checkbox.