An instance of the MdoUserControl class represents a custom control in the repository. You can build your own custom controls, or use controls that are supplied by an independent software vendor (ISV).
| Interface | Description |
| IMdoComponent | Maintains the relationship between a Visual Basic component and the Visual Basic project to which it belongs. |
| IMdoControlContainer | Maintains the relationship between a Visual Basic control container and the Visual Basic controls that it contains. |
| IMdoModelItem | Maintains properties that are common to many different types of MDO Model objects. |
| IRepositoryItem | Manages repository objects and relationships. |
| IRepositoryObject | Retrieves repository object identifiers. |
| IRepositoryObjectStorage | Creates and loads repository objects. |