Bundle creator OS Type code ??? in Xcode 4

Question

I just realized that Bundle Creator OS Type code in my iOS app's Info.plist value is ????? in Xcode 4. What is the value supposed to be?

Answer 1

It's used to identify your application. You don't have to change it for an iPhone application.

Take a look at these links:

• Information Property List Key Reference

• Mac Creator and File Type Codes

• Data Type Registration

Answer 2

It's not really used anymore. It's a holdover from the Classic Mac OS days when it was a datapoint used mainly to determine what apps could create or edit or read file types. Back then you had to register them with Apple. I don't think they even provide that service any more. OS X and some apps might still use it in rare cases under the hood but its very legacy. As you can imagine, the severely limited possible permutations made it untenable long term.

UTIs are the preferred approach now. The system then uses a combination of these and file extensions and magic numbers. Though on ios that may not be true as much as OSX.