Technology
XSLT (Extensible Stylesheet Language Transformations)
Definition
XSLT is a declarative programming language for transforming XML documents into other formats such as HTML, PDF, or other XML structures. In the e-invoicing domain, XSLT stylesheets are used to convert XRechnung or ZUGFeRD XML files into human-readable HTML or PDF representations. KoSIT provides official XSLT stylesheets for visualising XRechnung documents.
Switch to German:XSLT (Extensible Stylesheet Language Transformations) (DE)
Related terms
XPathXPath (XML Path Language) is a query language for XML documents that enables addressing nodes and values in an XML tree. In the e-invoicing context, XPath is used in Schematron rules to specifically address individual fields of an invoice (e.g., BT-1 or BT-9) and check their content against business rules. Developers also use XPath in XSLT transformations for rendering e-invoices.XRechnungXRechnung is the German standard for structured electronic invoices in public sector procurement (B2G). It is based on the European standard EN 16931 and is available in two syntaxes: UBL 2.1 and UN/CEFACT CII. Since 27 November 2020, federal public buyers have been required to accept electronic invoices in XRechnung format, and state and municipal authorities have been progressively included.ZUGFeRDZUGFeRD (Zentraler User Guide des Forums elektronische Rechnung Deutschland) is a hybrid invoice format that combines a human-readable PDF/A-3 file with embedded machine-readable XML data. The format is maintained by the Forum elektronische Rechnung Deutschland (FeRD) and exists in several profiles (MINIMUM, BASIC, EN 16931, EXTENDED). It is technically identical to the European Factur-X standard.KoSIT (Coordination Office for IT Standards)The Coordination Office for IT Standards (KoSIT) is an institution of the Free Hanseatic City of Bremen that develops and maintains IT standards for public administration on behalf of the IT Planning Council of Federal and State Governments. KoSIT is responsible, among other things, for maintaining the XRechnung standard, the open-source Validator tool, and operating the national Peppol infrastructure in Germany.XRechnung Validator (KoSIT)The XRechnung Validator is a command-line tool developed by KoSIT and released as open source for checking XRechnung documents for conformity. It validates both XML schema validity (XSD) and content-level business rules via Schematron. The tool is regularly updated when new XRechnung versions are released and serves as the reference implementation for validation.