Identifying Windows for Accessibility Aids
You should try to give different types of windows separate, unique window classes so that accessibility aids can identify their function.
Accessibility aids sometimes need to specialize their handling of different windows within the same application. For example, an application that has both a word-processing window and a spreadsheet window might draw the visual focus indicator in very different ways. Screen review utilities may also have separate instructions for handling these windows, such as identifying areas of the window that should automatically be read to the user whenever they change. Voice input and on-screen utilities also allow the user to choose between names to move focus to the window.
While a human being can identify a window by its title, this is not a reliable mechanism for accessibility aids, because many window titles change dynamically with the document or the status, or are localized into different languages. The window class name does not change under either circumstance.