This dialog is available from the Window / Edit Window Title... menu command from the Graphs window.
This dialog box allows you to customize the title of this graph window. The title is shown at the top of the window, and under the Window menu command where open windows are listed. You can either select to use the default window title, which includes the graph type and active sub-portfolio, or you can enter your own title. When entering your own title you can include fields to insert either the graph type or active sub-portfolio by pressing the Insert Field... button.