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This structure represents the unique key fields associated with identifying a Invoice . Invoice s Invoices can be identified by InvoiceNumber or InvoiceUid. When specifying a PwsInvoiceRef as an input to a web service, you may specify one or both the InvoiceNumber and/or InvoiceUid. However, if you do specify both, they must both refer to the same Invoice Invoice or the Invoice reference will not be considered valid. When a PwsInvoiceRef is returned in the response to a web service, both the InvoiceNumber and InvoiceUid will be populated, and guaranteed to refer to a single Invoice.
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