title: When can an IDWriteFontFace have more than one file?
body: <p><code>IDWriteFontFace.GetFiles()</code> returns a collection of font files. This puzzles me because I don't know of any font format which can split a single font face across multiple files. (The reverse is not the case; a font collection file can hold multiple font faces.)</p>
  
  <p>Indeed, testing against the installed fonts on my computer I observed that this method always returns a collection containing exactly one file.</p>
  
  <p>Question: are there cases where <code>IDWriteFontFace.GetFiles()</code> returns more than one file?</p>