What is it? Schematron validation?
Short answer
Schematron is the XPath-based generic validation language used to control business rules XML documents. Contrary to XSD does not control structure XML, but logical correctness and consistency of the data for example, whether TaxInclusiveAmount = TaxExclusiveAmount + TaxAmount, totals, mandatory references or VAT recap. EN 16931 is validated in most implementations using files Schematron; Type error codes BR-CO-10 mean Business Rule - Calculation, PEPPOL-EN16931-Rxxx are profile-specific rules Peppol.
This element exists"
XSD check only the presence and shape of the element - not whether it makes sense.
"The account must sit."
For example: TaxInclusiveAmount = TaxExclusiveAmount + TaxAmount. Or: if InvoiceTypeCode = 380, there must be additional mandatory data XSD He doesn't know.
How to Read a Bug
BR = Business Rule, CO = Calculation (calculations) BR-CO-10, BR-CO-15. PEPPOL-EN16931-Rxxx are profile-specific rules Peppol.
Local validation rules
Slovak transposition and validation rules can add additional controls on general Peppol framework.
Conclusion
Not legal advice. Machine-translated answer, not yet manually reviewed. For the exact wording, see the Slovak original.