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Maven includes a special qualifier string called snapshot. This is can be any standard version string that ends with the qualifier "-SNAPSHOT". Snapshot version are handled differently than the standard version strings in that Maven does not assume these artifacts are static. Snapshot artifacts are intended to be temporary release builds and therefore will change and/or be removed over time.
Project Version Parsing
The code used to parse a version string in Maven can be found in the public svn repository.
*http://svn.apache.org/viewvc/maven/components/archive/maven-2.1.x/maven-artifact/src/main/java/org/apache/maven/artifact/versioning/DefaultArtifactVersion.java?view=markup
*http://svn.apache.org/viewvc/maven/maven-3/trunk/maven-compat/src/main/java/org/apache/maven/artifact/versioning/ComparableVersion.java?view=markup