What does "InfoDictionary version" signify in information property list (plist file)?

What does "InfoDictionary version" signify? It is definitely different from the bundle version, but wh开发者_如何学Goat is the role of "InfoDictionary version"?

"InfoDictionary version" signifies the version information for the Info.plist format. See Apple's doc for CFBundleInfoDictionaryVersion for details.

CFBundleInfoDictionaryVersion (String - iOS, macOS) identifies the current version of the property list structure. This key exists to support future versioning of the information property list file format. Xcode generates this key automatically when you build a bundle and you should not change it manually. The value for this key is currently 6.0.