title: What does "Document is distributed as a bundle" mean?
body: <p>I am using Xcode 7.3.1 to create a Cocoa document based application. I notice that in the Document Types info panel there is an option that I don't understand. It says "Document is distributed as a bundle" and it looks like this.</p>
  
  <p><a href="https://i.stack.imgur.com/gBVBH.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/gBVBH.jpg" alt="Bundle Option Screenshot from Xcode"></a></p>
  
  <p>I found that this option controls the <code>LSTypeIsPackage</code> key for <code>CFBundleDocumentTypes</code> in the app's Info.plist file. I was able to find only two explanations of the usage of this key in Apple's official documentation. Both were very brief entries in relatively large tables.</p>
  
  <p>The first explanation from the <a href="https://developer.apple.com/library/mac/documentation/DataManagement/Conceptual/DocBasedAppProgrammingGuideForOSX/ApplicationCreationProcess/ApplicationCreationProcess.html" rel="nofollow noreferrer">App Creation Process Overview</a>. It is very brief and offers no more information than the screenshot above.</p>
  
  <blockquote>
    <p>A Boolean value specifying whether the <strong>document is distributed as a bundle</strong>. If NO, omit this value.</p>
  </blockquote>
  
  <p>The second explanation is a little more helpful. It comes from the Mac Developer Library's <a href="https://developer.apple.com/library/mac/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html#//apple_ref/doc/uid/TP40009249-101685-TPXREF107" rel="nofollow noreferrer">Information Property List Core Foundation Keys Reference</a>.</p>
  
  <blockquote>
    <p>Specifies whether the document is distributed as a bundle. If set to true, the bundle directory is treated as a file. (In OS X v10.4 and later, this key is ignored if the LSItemContentTypes key is present.)</p>
  </blockquote>
  
  <p>It almost sounds as if this option affects how the application bundle itself is treated by the OS. If that's the case then I really have no idea what to make of these descriptions.</p>
  
  <p>I know that many document types (such as <code>.xcodeproj</code> documents) are actually directories. Does this setting control whether documents are directories?</p>