SPList.RootWebOnly property

Property that indicates whether the option to allow deployment to root Webs only.

Namespace:  Microsoft.SharePoint
Assembly:  Microsoft.SharePoint (in Microsoft.SharePoint.dll)

public bool RootWebOnly { get; set; }

Property value

Type: System.Boolean
A Boolean value = true if deployment is allowed on root Webs only.

This property is false by default for lists. Setting this property to true for a list not on a root web throws a [System.NotSupportedException] exception.