to 1997. In 1998, Kent Spackman was appointed to chair this committee and spearheaded the transformation of the multi-axis systems into a highly computable form (See SNOMED CT): a directed acyclic graph anchored in formal representation logic. In 2007, the newly formed International Health Terminology Standards Development Organisation (IHTSDO) acquired all the Intellectual Property of SNOMED CT and all antecedent SNOMED versions. Brief timeline: 1965 SNOP 1974 SNOMED 1979 SNOMED II 1993 SNOMED International 3.0 1995 SNOMED Microglossary of Signs and Symptoms 1993-98 SNOMED International versions 3.1-3.5 2002 First release of SNOMED CT 2007 All versions of SNOMED acquired by IHTSDO 2017 All SNOMED versions except SNOMED CT have been formally deprecated by IHTSDO Reference ontology SNOMED was designed from its inception with complex concepts defined in terms of simpler ones. For example, a disease can be defined in terms of its abnormal anatomy, abnormal functions and morphology. In some cases, the etiology of the disease is known and can be attributed to an infectious agent, a physical trauma or a chemical or pharmaceutical agent. Multi-axial design The current concept uses eleven (11) axes that comprise terms organised in hierarchical trees. The axes and some examples are provided below: T (Topography) – Anatomic terms (T-28000) Lung (T-32000) Heart (T-51000) Mouth (T-D2500) Hip (T-D9600) Heel M (Morphology) – Changes found in cells, tissues and organs (M-40000) Inflammation (M-44000) Granuloma (M-54700) Infarcted (M-54701) Microscopic infarct For the Morphology axis, SNOMED has agreed to collaborate and use the same harmonized codes shared with International Classification of Diseases for Oncology. Additional examples on topology are provided on that page. L (Living organisms) – Bacteria and viruses (L-21801) Mycobacterium tuberculosis (L-25116) Streptococcus pneumoniae C (Chemical) – Drugs (C-C137A) Bufferin Analgesic Tablets (C-C137B) Bufferin Analgesic Caplets F (Function) – Signs and symptoms (F-03003) Fever J (Occupation) – Terms that describe the occupation Kindergarten teacher (13420) Computer programmer (08420) Doctor (06105) Professional Nurse (General) (07110) Beautician (57040) D (Diagnosis) – Diagnostic terms (D-13510) Pneumococcal pneumonia (D-14800) Tuberculosis (D3-15000) Myocardial infarction P (Procedure) – Administrative, diagnostic and therapeutic procedures A (Physical agents, forces, activities) – Devices and activities associated with the disease S (Social context) – Social conditions and important relationships in medicine (S-10120) Mother G (General) – Syntactic linkages and qualifiers See also Diagnosis code Drug class DOCLE Medical classification SNOMED CT Medical Dictionary for Regulatory Activities (MedDRA) Pathology Messaging Implementation Project References External links Official page