As far as I understood. Once the PR Card applications are linked to GCKey, IRCC updates the PR Card application's Final Decision twice. However, most of the times applicants don't receive any notifications during these updates. Hence these updates are called Ghost Updates (GU1 and GU2). GU1 usually means that your photo is accepted and is in queue for PR card printing. GU2 is when it will show in your GCkey that your PR Card is printed and mailed to your address.What are GU1 and GU2?