title: Using built in bar button icons
body: <p>In reading <a href="https://developer.apple.com/library/ios/documentation/UserExperience/Conceptual/MobileHIG/BarIcons.html#//apple_ref/doc/uid/TP40006556-CH21-SW1" rel="nofollow">Apple's guide</a> on <code>BarButtonItems</code>, I see that several bar button icons exist which are not choosable from the Attributes inspector in Xcode (in particular the large "chevron" which appears in 4 orientations.</p>
  
  <p>I've searched for a way to access them, but cannot find one. Does this mean that they are internal and only accessible to Apple's own application and I'm not permitted to use them in my own application?</p>