- Indicates that a toolbox item filter string is allowed, but not required.
- Indicates that custom processing is required to determine whether to use a toolbox item filter string. It is typically specified on a root designer class to indicate that the designer wishes to accept or reject a toolbox item through code. The designer must implement the GetToolSupported(System.Drawing.Design.ToolboxItem) method of the IToolboxUser interface.
- Indicates that a toolbox item filter string is not allowed. If a designer and a component class both have a filter string and the value of one is ToolboxItemFilterType.Prevent, the toolbox item will not be available.
- Indicates that a toolbox item filter string must be present for a toolbox item to be enabled. For a toolbox item with a filter type of Require to be enabled, the designer and the component class must have a matching filter string. Additionally, neither the designer or component class can have a filter type of Prevent for the toolbox item to be enabled.