Explanation
Ref:
https://docs.oracle.com/en/cloud/saas/project-portfolio-management/19a/oapfm/project-foundation-configuration Topic - Associating Project Types and Class Categories: Examples Project classifications group your projects according to categories and codes that you define. When you associate project classifications with project types, the classification is available for selection on projects with that project type.
Use any of the following methods to associate class categories with project types:
* Add a classification to the project type definition
For each classification that you associate with the project type, you can enable the Assign to All Projects option to automatically add the classification to the project definition for all new projects with the project type.
When this option is enabled, all projects with this project type must be assigned a class code for the class category.
* Add a project type to the class category definition
* Enable the Assign to all Project Types option on the class category definition