The Sonatype book says that an include element in the assembly descriptor may be groupId:artifactId:classifier:type ( http://www.sonatype.com/books/mvnref-book/reference/assemblies-sect-controlling-contents.html). It may of course be other things as well.
The maven-assembly-plugin documentation says that this include element can be groupId:artifactId:type:version[:classifier] ( http://maven.apache.org/plugins/maven-assembly-plugin/assembly.html#class_dependencySet ). Which is it? Best, Laird -- http://about.me/lairdnelson