# IHelp interface

Namespace: [Rhino.UI](https://developer.rhino3d.com/api/rhinocommon/namespace/rhino.ui.md) · Assembly: [RhinoCommon](https://developer.rhino3d.com/api/rhinocommon/assembly/rhinocommon.md)

```cs
public interface IHelp
```

Implement this class to add help to a modeless UI panel.

## Properties

- [HelpUrl](https://developer.rhino3d.com/api/rhinocommon/type/rhino.ui.ihelp/helpurl.md): Help topic URL which gets passed to RhinoHelp.Show