You can view the extensions made to the schema of any tree. This includes all classes and attributes added to the base schema (the schema that shipped with the product). You might want to do this to determine what types of classes and attributes have been added. It might also be useful while troubleshoooting to help you narrow your focus to the extensions only.
Some schema extensions are made apparent when icons display next to class names in class lists: When a class is added to the schema, it is automatically assigned the Unknown class icon.
NOTE: The Unknown class is part of the base schema.
Click Object > Schema Extensions.
Click the tree icon, select a tree, and then click OK.
Your current tree is the default, but you can select another tree.
Click OK.
If you want to print the results, click Print, complete the Print dialog box, and then click OK.
When finished viewing the results, click Close.