A metamodel has two version identifiers: a base version and an optional custom version. Initially, a metamodel only has a base version defined. When customizing your metamodel you have the opportunity to assign an additional custom version. Once you have assigned a custom version, you can update it anytime after making new customizations. Assigning a custom version is optional.
Example of a customized metamodel with a base version and custom version
If you have not assigned a custom version to your customized metamodel before, the Metamodeler will notice when you validate your customizations, or when validation is performed when you apply or export your customizations. A message window will appear asking you if you want to set a custom version. Example:
Click Yes if you want to assign a version. In the window that appears, enter a custom version, and click OK.
Click No if you do not (yet) want to assign a version. You can always assign a custom version via the metamodel package's Properties window.
To assign a custom version to your customized metamodel or to update the custom version, select the metamodel package in the model browser, and double-click the custom version property in the package's Properties window. Enter the (new) value in the window that appears, and click OK. Your customized metamodel now has a(n updated) custom version.