versionSpecifier
A version string used to pin a library, model, code system, or value set to a specific version. Expressed as a string literal following the version keyword.
Examples
Semantic version for a library
library MyLib version '1.0.0'
Version for an included library
include FHIRHelpers version '4.0.1' called FHIRHelpers
Version for a code system
codesystem "LOINC": 'http://loinc.org' version '2.72'
EBNF
versionSpecifier : STRING ;