Bikeshedding QoS / priority naming to get the discussion going 
/// Describes the priority of a task.
enum Priority: Int, Comparable {
/// For urgent and important work.
/// In user interfaces this could be user interactions, such as animations, event handling, or updating the user interface.
case critical
/// For high priority work blocking other parts of the system (or the end user).
/// In user interfaces this could be a task initiated by the user, which the user is actively waiting on.
case highPriority
/// Default priority for tasks.
case normal
/// Priority for a utility function that e.g. could have a progress bar.
case longRunning
/// Priority for maintenance or cleanup tasks.
case background
}