You can extend the metadata stored in the repository by associating information with individual repository objects. For example, you may want to store contact information with the sources you create. If you create an Aggregator transformation, you may want to store an email address with that transformation. You associate information with repository objects using metadata extensions.
Repository objects can contain both vendor-defined and user-defined metadata extensions. You can view and change the values of vendor-defined metadata extensions, but you cannot create, delete, or redefine them. You can create, edit, delete, and view user-defined metadata extensions and change their values.