The Foundation Component represents the entire WHO-FIC universe. It is a multidimensional collection of interconnected entities and synonyms.
These entities consist of diseases, disorders, injuries, external causes, signs and symptoms, functional descriptions, interventions, and extension codes.
ICD-11 statistical core (MMS) is derived from this foundation, ICF and ICHI will follow.
The entities in the Foundation Component:
are not necessarily mutually exclusive
allow multiple parenting ( i. e. an entity may be in more than one branch, for example tuberculosis meningitis is both an infection and a brain disease)
A linearization is a subset of the foundation component, that is:
Fit for a particular purpose: reporting mortality, morbidity, or other uses
Composed of entities that are Mutually Exclusive of each other
Each entity is given a single parent
Linearizations are similar to the classical print versions of ICD Tabular List (e.g. volume I of ICD-10 or other previous editions).
Various linearizations could be built at different granularity,
use case or other purposes such as for Primary Care, Clinical Care or Research. The linkage from the foundation component to a particular
linearization will ensure consistent use of the classifications.