Dynamics Community Forum Thread Details

How to detect Credit Note / Debit Note for posted Sales invoice (D365FO)?

Context

Printing is triggered after posting from SalesInvoiceJournalPrint.printJournal(Set _journalList) (extension).
I can print my custom report successfully after posting.
I also added a manual print button on CustInvoiceJournal (multi-select) and it works.

Problem

In Thai localization, I found CustInvoiceTableExtensionTH.NoteFormat (enum TaxUnrealizedSalesNoteFormat) which can indicate CN/DN.
However, for many posted invoices created from Sales order “Credit invoicing”, CustInvoiceTableExtensionTH.NoteFormat is empty/None, but the standard output still prints with “Credit Note” title.
Therefore, NoteFormat is not populated in all flows, and Number sequence is not reliable.

Questions

In standard D365FO, what is the correct source of truth to decide “Invoice vs Credit Note vs Debit Note” for sales invoices?
Which table/field does standard logic use (e.g., CustInvoiceJour.InvoiceAmount sign, CustInvoiceTrans quantities, correction/reversal flags, references to original invoice, etc.)?
For Thai DN/CN documents: is there a standard field (or doc type) that is always set for DN (not just “amount > 0”)?
Is there a recommended API / method to reuse (e.g., a standard method that returns the document title/type, similar to SalesInvoiceContract.parmDocumentTitle() or something in SalesFormLetter_Invoice / SalesInvoiceJournalPrint)?
If NoteFormat is only used by some TH scenarios, when is it supposed to be populated, and by which class/table update?
Best practice for custom report header: should we implement a fallback like “if NoteFormat empty -> use amount sign for CN, otherwise use NoteFormat for DN/CN”, or is there a better approach?