SBML Level 3 Version 1 Core Schemas
Past levels of SBML were accompanied by XML Schema definitions, but is not possible to use XML Schema to completely characterize the syntax of SBML Level 3 because certain constructs allowed by Level 3 cannot be defined in XML Schema. However, it is possible to use RELAX NG schemas. We provide RELAX NG schemas that describe the valid syntax of an XML document.
Please see the SBML Level 3 RELAX NG schemas page for more information.