The diagram above defines the class VecContent which is intended to be regarded as the top level root element for VEC documents. It is the declared entry point to the information that a VEC file contains. Furthermore it is intended to facilitate the mapping of the VEC model to a XSD schema definition.
A VecContent is a container for various DocumentVersions, PartVersions, Projects, ItemHistoryEntries, CopyrightInformations, Units, Contracts and ConformanceClasses. DocumentVersion and PartVersion are the only two classes in the VEC model that define contain version information. Almost all information a VEC document can contain is subordinated to one of those two classes. This means in the end that every piece of information which is represented as an instance of a class of a certain attribute value is distinctly related to a dedicated PartVersion or DocumentVersion.
The only exceptions are classes with the stereotype <<constant>> as shown in the diagram.