Oh. OK. That's a relief, anyway!
So, indeed, 'authorised' or not is really of concern to the parents or child. The, "A will not be in school next so-and-so because (reason)," required for politeness' sake, will do.
... But if the child is absent too often (more than five times, I think someone said?), matters may escalate; fines and ultimately prosecution on non-payment thereof will get mentioned. Is that about it?
Perhaps not too unreasonable. I think of the times (there were a few) when one of my children was off school for extended periods; thinking back, I suppose I was pleased when the school got in touch to check on them.
No-one ever threatened us with a fine, back in the day. Are we better off as a society now school absences are quasi-judicial in this way? I wonder. Part of social engineering, I suppose: good or bad? Hmm.