title: ios apps can download the following fonts if necessary
body: <p>In the iOS 7 font list located here, <a href="http://support.apple.com/kb/HT5878">http://support.apple.com/kb/HT5878</a>, there is a section at the bottom with the heading "apps can download the following fonts if necessary".</p>
  
  <p>What does this mean?
  How does one include these fonts, and how is this different than including custom fonts?</p>