ClaML format and its use in the dissemination of WHO Classifications


The "Classification Mark-up Language (ClaML)" is an XML based format designed specifically for classifications. It was accepted as European norm (CEN/TS 14463) and as an international norm (EN ISO 13120:2013)

WHO decided to use this format to share its classifications such as the ICD.


This format allows us to capture

·         information on the classification hierarchy (i.e. parent child relations)

·         A level of granularity that allows identifying different rubrics within the classification categories. (Title, includes, excludes, definitions, coder instructions, etc. are separated from each other)

·         Cross references



The main XML elements used in this format are the following:

·         The main element (root element) is "ClaML" for the definition of the classification as such.

·         The element "Class" is used for the definition and structuring of the chapters, groups and categories. The classes define their parent and children classes by using "SuperClass" and "SubClass" elements so that the hierarchical representation is captured.

·         Each "Class" may have one or more "Rubric"s which are used to define different aspects of that class. For example, title, inclusions, exclusions are separate Rubrics under a "Class" element.

·         A "Reference" tag can be used to identify the cross references within the classification.

·         The element "ModifierClass" and "Modifier" are used for the definition and integration of subclassifications (Modifiers), in the ICD-10 as list of codes for the fourth and possible fifth character of the codes.