In short, 10.7.3 introduced "bookmarks". Basically your app can ask for permission to read/write to a file/folder, and keep that permission indefinitely. Prior

In short, 10.7.3 introduced "bookmarks". Basically your app can ask for permission to read/write to a file/folder, and keep that permission indefinitely. Prior to that, if you wanted to write somewhere on the disc (say the Downloads folder) you'd have to use the sandbox save dialog every time. Now you ask once for permission, and keep a bookmark of that permission. There is also a document-scoped version of bookmarks. Not clear on the use case for that.