Is it possible to have multiple document types for one NSPersistentStoreCoordinator?

I have 2 different entities in my core data model: project and issue. Each type has unique attributes, so I want to use different UTI document type for each entity. Each UTI document type should have an extension. Unfortunately, NSPersistentStoreCoordinator allow开发者_JAVA技巧s to set only one file extension.

So my question how to export more than one document type with the same extension.

Have you tried something like this in target->Get Info->Properties:

I haven't tested, but I assume something like this would work.

It's impossible (Mac OS X 10.6).