I do understand what is there in the SDK help but when you see difference in the .pkg file with pUid and private path for backup-registration, then first question would come up in your mind is why it differs. Now it's responsibility of poster to describe it in detail. Has he used unique pUid or the same as secure id? People generally do not use unique pUID, rather they use SID.(I do not have statistical data though) And my answer was in the consequence of this.