I'm inheriting TextBox in my custom control...it has a property that is
type TextBox and will point to two other TextBox controls on the form.

This is working correctly, however at design time, the Property Browser
displays a "+" sign when the property is set to a control other than
(none).  This toggles the detail of the TextBox that the property value
points to.

Is there an attribute I can apply to the property declaration that will
control whether this little plus-minus detail is available at design
time in the Property Browser?  It would be inappropriate in my case to
be able to modify the underlying properties of the control pointed to by
the property, as this control is
always available at design time.

I've declared the property as such:

<DesignerSerializationVisibility(DesignerSerializationVisibility.Visible
)> _
Public Property StateTextBox() As TextBox
 Get
   Return _StateTextBox
 End Get
 Set(ByVal Value As TextBox)
   _StateTextBox = Value
 End Set
End Property
Private _StateTextBox As TextBox