...
In InforLN, there are some purchase invoices modified in a given period of time. Some of them are legitimate and some aren't because they were created by Stellarise Connector in the previous run.
When Stellarise Connector runs the next time, it must discard the ones that it has previously generated. To do this, the InforLN API provides an extra "Source" field, reporting the origin of the invoice. If it is empty, then it has been originated by InfoLN so it can be sent to Xero, otherwise the invoice is simply discarded.
InforLN Sales invoice wrong Ledger Code / Tax rates
...