Search the documents by an exact value: the whole search must equal the document number, customer name, customer tax number, reference or any metadata value, ignoring case (INV-123 finds inv-123, never INV-1234). To match one field only, write document.id:<value>, document.customer.name:<value>, document.customer.tax_registration_number:<value>, reference:<value> or metadata.<key>:<value> (quote a metadata key that contains a colon: metadata."<key>":<value>).