Server and non-transitory computer-readable storage medium storing computer-readable instructions

A non-transitory computer-readable medium storing computer-readable instructions for a server, the computer-readable instructions comprising instructions to implement:

• in a state where first combination data is stored in the memory, receiving a first request from a first external device, the first combination data including first account data and first device-identification data in association with each other, the first device-identification data identifying a first communication device, the first request including second account data different from the first account and requesting replacement of the first account data associated with the first device-identification data in the first combination data with the second account data;
• in response to receiving the first request from the first external device, determining whether priority assigned to the second account data included in the first request is higher than priority assigned to the first account data associated with the first device-identification data stored in the memory;
• based on a determination that the priority assigned to the second account data included in the first request is higher than the priority assigned to the first account data associated with the first device-identification data stored in the memory, replacing the existing first account data stored in the memory with the second account data included in the first request, thereby storing the second account data in the memory in association with the first device-identification data;
• and
• based on a determination that the priority assigned to the second account data included in the first request is not higher than the priority assigned to the first account data associated with the first device-identification data stored in the memory, not replacing the existing first account data stored in the memory with the second account data included in the first request.