The Notification Center lets you turn off notifications for a specific alarm. When disabled, you won't get any alerts for that alarm type. You can choose to disable notifications temporarily (for 1 or 8 hours) or permanently. This setting is personal; turning off notifications only affects your account, and other users will still receive their alerts.
When you disable notifications for an alarm, a personal rule is automatically created. To undo this, delete the rule. See 'Set up rules' for instructions. For temporary disables, the rule will be automatically removed after the chosen time period.

