Reference
Schematron
XSLT-based rule language used by KoSIT and Peppol to validate business rules in XML invoices.
Definition
XSLT-based rule language used by KoSIT and Peppol to validate business rules in XML invoices.
Explanation
Each rule (assert/report) carries an ID like BR-DE-15 or PEPPOL-EN16931-R046, which appears in validator output.
Schematron complements XSD: schemas check structure and types, Schematron checks cross-field arithmetic, conditional requirements, and code-list constraints.