Phantom stays according to Hyatt
Correct me if I am wrong, but I don't think I've seen this terminology on hyatt web site before.
Now web check in bonus T&Cs include this:
Failure to visit the Hyatt Express Check-In Kiosk or the front desk may result in your room being released as an early departure, and your payment card being charged one night's room accommodations. These stays are considered phantom stays. Phantom stays are not eligible for Hyatt Gold Passport points, credit toward tier status or participation in bonus points or other promotional offers. A phantom stay is described as a stay where a guest uses Hyatt Web Check-In or 1-800-CHECK-IN to check into a hotel but does not physically stay at the hotel.