We present MUSTARD, a multi-user dynamic random hole see-through display, capable of delivering viewer dependent information for objects behind a glass cabinet. Multiple viewers are allowed to observe both the physical object(s) being augmented and their location dependent annotations at the same time. The system consists of two liquid-crystal (LC) panels within which physical objects can be placed. The back LC panel serves as a dynamic mask while the front panel serves as the data. We first describe the principle of MUSTARD and then examine various functions that can be used to minimize crosstalk between multiple viewer positions. We compare different conflict management strategies using PSNR and the quality mean opinion score of HDR-VDP2. Finally, through a user-study we show that users can clearly identify images and objects even when the images are shown with strong conflicting regions; demonstrating that our system works even in the most extreme of circumstances.