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Indicates the person simply did not turn up to the event, or did not attend without giving notice as such.
Unavailable
This is used when someone might have been contacted and has responded indicating they're unavailable for this shift. This does not necessarily mean they're unavailable that day, or even only when the shift it on ... other factors such as the event location & logistics, roles available, etc may have also been why the person the person has indicated they're not available.
Changing the default status
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