document class
The system administrator defines document classes. It is a system property that specifies a type of document. Typically, a document class is a category like Invoices. When you add a document to a library, you must choose a document class.
The document class determines:
Which user properties apply to the document. User properties are values such as account numbers and names.
For an IS document, the default access rights. These determine who can see, modify, add annotations to, and delete the document. (Access rights for a CS are derived from the user profile of the user who adds the document.)
For an IS document, disposition properties. For documents in the IS library, these determine when the document becomes eligible for disposal by archiving or deletion.
You can modify the document class of a CS document but not of an IS document.