guidelines - What are the rules of using ellipsis on buttons

I read about the rules of using ellipsis (three dots ...) in a menu command:

Indicate a command that needs additional information (including a confirmation) by adding an ellipsis at the end of the label.

I wonder if there are rules/convention/recommendation of using them on a button's label, outside of a menu.

It seems that there is no use of ellipsis in Ribbons in Microsoft products, even though some of the button do initiate a process which requires additional information (see example below).

So when considering the label of a command button which requires additional information in a pop-up dialog, would you recommend adding ellipsis at the end?

Answer

The very page you link to says:

This doesn't mean you should use an ellipsis whenever an action displays another window—only when additional information is required to perform the action. For example, the commands About, Advanced, Help, Options, Properties, and Settings must display another window when clicked, but don't require additional information from the user. Therefore they don't need ellipses.

ie - in your example: Header and Footer is a button that does what it says - it brings up the header and footer information. It doesn't need additional information on order to bring up that dialog - it just does it - so it doesn't need an ellipsis.

The Mac OS X Human Interface Guidelines state (And I've not included all the text here)

Use an ellipsis in the name of a button or menu item when the associated action

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  Requires specific input from the user.

  
  

  You can think of commands of this type as needing the answer to a specific question (such as "Find what?") before executing.

  
  


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  Is performed by the user in a separate window or dialog.

  
  

  To see why such commands must include an ellipsis, consider that the absence of an ellipsis implies that the application performs the action for the user. For example, if the Customize Toolbar command does not include an ellipsis, it implies that there is only one way to customize the toolbar and the user has no choice in the matter.

  
  


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  Always displays an alert that warns the user of a potentially dangerous outcome and offers an alternative.

  
  

  For example, Restart, Shut Down, and Log Out all use an ellipsis because they always display an alert that asks the user for confirmation and allows the user to cancel the action. Note that Close does not have an ellipsis because it displays an alert only in certain circumstances (specifically, only when the document or file being closed has unsaved changes).