In the Schema tab, you can specify a default schema for Oxygen XML Author Eclipse plugin to use if a document does not contain a schema declaration and no default validation scenario is associated with it.
To open the Schema tab of the Document type configuration dialog box, open the Preferences dialog box , go to Document Type Association, use the New, Edit, Duplicate, or Extend button, and click on the Schema tab.
This tab includes the following options for defining a schema to be used if no schema is
detected in the XML file:
- Schema type
- Use this drop-down list to select the type of schema.
- Schema URI
- You can specify the URI of the schema file. You can
specify the path by using the text field, its history drop-down, the
Insert Editor
Variables button, or the browsing actions in the 
Browse drop-down list.Tip: It is a good practice to store all resources in the framework directory and use the ${framework} editor variable to reference them. This is a recommended approach to designing a self-contained document type that can be easily maintained and shared between multiple users.