ISO 13120:2013

The main purpose of ISO 13120:2013 is to formally represent the content and hierarchical structure of healthcare classification systems in a markup language for the safe exchange and distribution of data and structure between organizations and dissimilar software products.
The scope of healthcare classifications systems covered in ISO 13120:2013 encompasses terminologies, and is constrained to traditional paper-based systems (like ICD-10) and systems built according to categorial structures and a cross thesaurus (like ICNP). ISO 13120:2013 is intended for representation of healthcare classification systems in which classes have textual definitions, hierarchical ordering, named hierarchical levels (such as "chapter", "section"), inclusion- and exclusion criteria, and codes. It is not intended to cover any formal representation, either for definition or composition, of concepts, or for specification of classification rules. Systems with such formal specifications can at best be partially represented using ISO 13120:2013, and are hence out of scope.
ISO 13120:2013 is not intended to:

provide a normative syntax on how a healthcare classification system is to be constructed;
define link types between elements in a healthcare classification system; this is left to the developers of healthcare classification systems;
provide a representation for direct viewing or printing.