This case-sensitive code system http://hl7.org/fhir/version-algorithm defines the following codes:
Code
Display
Definition
semver
SemVer
Uses the semantic versioning scheme as defined in [semver.org](http://semver.org).
integer
Integer
Versions are integers and ordered numerically
alpha
Alphabetical
Simple alphabetic sort on a case-insensitive and accent-insensitive basis. (Sorting of different cases or accented versions of a character is indeterminate)
date
Date
Versions are expressed as an ISO date/time syntax (including syntaxes with only portions of a date)
natural
Natural
Sorted according to the algorithm defined here: [naturalordersort.org](http://www.naturalordersort.org/)