Detect VOIDed invoices from quickbooks

Our system pulls lots of data from quickbooks using the QBWC/QBXML.
We also poll TxnDeletedQuery to get a list of deleted invoices, etc...

How do I query for or detect a 'Voided' invoice? I don't see anything in the InvoiceQueryRs schema that would indicate a voided invoice.
Does quickbooks do anything but zero-out the line item quantities?

Thanks!

The only thing QuickBooks does when voiding is:

• sets the quantities/rates to zero
• adds a "VOID" string to the Memo field

To detect it, you'd have to parse the Memo field and look at the rates/quantities. There's no way to filter by it in a query unfortunately.