Taxonomies

Codes are how meaning survives the journey between systems.

International

System	Covers
SNOMED CT	Clinical terms: findings, procedures, organisms, substances.
LOINC	Laboratory and clinical observations.
UCUM	Units of measure.
ICD-10	Classification of diseases, for statistics and reimbursement.

System	Covers
dm+d	Dictionary of medicines and devices.
SNOMED CT UK Edition	The national extension.

Other nations will follow. The primitives treat the code system as a parameter, never a constant.