Overview
ISO/IEC 19757-3:2025 defines Schematron, a rule‑based schema language for validating XML documents as part of the Document Schema Definition Languages (DSDL) family. The standard establishes the syntax, semantics and conformance requirements for Schematron schemas and describes when an XML document matches the patterns and assertions expressed in a Schematron schema. Schematron relies on query languages such as XPath (and bindings for XSLT, XQuery, XPath versions) to write expressive assertions and reports.
Key topics and technical requirements
- Core syntax and elements: normative definition of Schematron elements such as schema, pattern, rule, assert, report, let, include, extends, group, phase, value-of and ancillary elements/attributes (diagnostic, severity, properties, title, ns, param, etc.).
- Well‑formedness and namespace rules, whitespace handling and minimal syntax requirements.
- Semantics and processing model: formal validation function, abstract pattern processing, order/side‑effect behavior, localization/language fixup and base URI fixup.
- Query language binding: normative bindings for multiple query/execution environments (Annexes cover XSLT2/3, XPath2/3/3.1, XQuery3/3.1 and default bindings).
- Conformance: definitions for simple conformance and full conformance of Schematron processors and schemas.
- Normative and informative annexes: RELAX NG schema for Schematron, extra constraint schemas, default query binding, and examples. Annex D describes the Schematron Validation Report Language (SVRL) for standardized reporting.
Practical applications and who uses it
- XML authors and schema designers who need rule‑based validation that complements grammar-based schemas (RELAX NG, XML Schema).
- Quality‑assurance and data validation teams who require expressive business rules, cross‑element constraints and readable error reporting.
- Tool developers and integrators building Schematron processors, validators or reporting tools (must implement query language bindings and conformance rules).
- Standards bodies and document publishers that embed business or editorial rules in technical document processing pipelines.
- Use cases include document quality checks, complex content constraints, conditional validation based on context/phase, and multi‑lingual validation workflows.
Related standards & keywords
- Related DSDL parts and XML schema technologies (RELAX NG, XML Schema).
- Keywords: ISO/IEC 19757-3, Schematron, DSDL, XML validation, rule-based validation, XPath, XSLT, XQuery, SVRL, query language binding, conformance.
This standard is essential when you need an ISO‑level, interoperable definition of Schematron for robust, rule‑oriented XML validation and standardized reporting.
Open preview (PDF)Information technology — Document Schema Definition Languages (DSDL) — Part 3: Rule-based validation using Schematron
