Alcance
ISO/IEC 13250-3:2013 defines an XML-based interchange syntax for Topic Maps, which can be used to interchange instances of the data model defined in ISO/IEC 13250-2. It also defines a mapping from the interchange syntax to the data model. The syntax is defined with a RELAX-NG schema, and more precision is provided through the mapping to the data model, which effectively also defines the interpretation of the syntax.