An iCloud display set allows multiple iCloud apps to use a single entry in the iCloud Documents & Data user settings. Each app still writes data to its container, and the display set references the storage used for all the containers.
For example, you might provide a custom calendar app, a task-list app, and an alarm clock app that have their own iCloud containers, each of which shows up in users’ Documents & Data settings in iCloud. If you wanted to have users configure data storage for these apps in a single setting, you could create an iCloud display set called NotifyMe that included the containers for all three apps:
iCloud.MyCalendar
iCloud.MyTasks
iCloud.MyAlarm
The user would see only the NotifyMe display set when configuring iCloud to store data for these apps.