| BuiltInDocumentPropertyCollection | A collection of built-in document properties. |
| ContentTypeProperty | Represents identifier information. |
| ContentTypePropertyCollection | A collection of ContentTypeProperty objects that represent additional information. |
| CustomDocumentPropertyCollection | A collection of custom document properties. |
| CustomProperty | Represents identifier information. |
| CustomPropertyCollection | A collection of CustomProperty objects that represent additional information. |
| DocumentProperty | Represents a custom or built-in document property. |
| DocumentPropertyCollection | Base class for BuiltInDocumentPropertyCollection and CustomDocumentPropertyCollection collections. |