The code generator Accessorizer has an option to assign IBOutlets rather than retaining them. For example, compare these two generated lines:
@property(nonatomic,retain)IBOutlet UIImageView *backgroundView;
@property(nonatomic,assign)IBOutlet UIImageView *backgroundView;
Why would I want to assign IBOutlets, while retaining all other properties?
Usage depends on the platform as specified in the memory management guide :