For the curious, there is a detailed discussion of the ellipsis in menus in the Macintosh Human Interface Guidelines (PDF):
http://interface.free.fr/Archives/Apple_HIGuidelines.pdf
Search for "ellipsis" or go to pages 91-95 of the PDF (labeled as pages 67-71), in particular:
> The ellipsis character doesn’t simply mean that a dialog box or window will appear. For example in the Finder File menu, the Get Info command doesn’t have an ellipsis character and shouldn’t. When you select a Finder object and choose Get Info, a window appears displaying information about the object. The window appearing simply completes the command. The command doesn’t require additional input from the user before it executes.
Also in the Windows 95 Interface Guidelines (PDF):
https://www.ics.uci.edu/~kobsa/courses/ICS104/course-notes/M...
Again search for "ellipsis" or go to page 109 of the PDF (labeled along with several other pages as page 143):
> If you provide access to copyright and version information for your application, include an About application name command on this menu. When the user chooses this command, display a window containing the application's name, version number, copyright information, and any other informational properties related to the application. Display this information in a dialog box or alternatively as a copyright page of the property sheet of the application's main executable (.EXE) file. Do not use an ellipsis at the end of this command because the resulting window does not require the user to provide any further parameters.