Platform-specific error information can be obtained from a CfsError instance by means of the following messages. These messages return nil if not supported by a particular platform or in the case of a synthetic error that is simulated for compatibility rather than being generated by the platform operating system itself.

Platform-specific error information is useful for debugging, and appears as four integers, separated by commas, between square brackets when a CfsError prints itself. If necessary, these methods can be used to trigger special platform-specific actions. However, this will of course result in nonportable code.