Hi, in context or linear menu ? because in context i afraid it is not possible.
In linearmenu you can use:
Inventor 2025 Help | CommandControls.AddSeparator Method | Autodesk
Private Sub OnLinearMarkingMenu(ByVal SelectedEntities As Inventor.ObjectsEnumerator, ByVal SelectionDevice As Inventor.SelectionDeviceEnum,
ByVal LinearMenu As CommandControls, ByVal AdditionalInfo As Inventor.NameValueMap) Handles oUserInputEvents.OnLinearMarkingMenu
For Each control As CommandControl In LinearMenu
If control.InternalName = "DrawingAddRowToRevisionTableCtxCmd" Then
Try
Call LinearMenu.AddSeparator(control, False)
Catch ex As Exception
End Try
End If
Next
End Sub