This is when the school asks parents/carers to keep children at home without the child being formally excluded. Although schools may give the impression that they are doing you and the child a favour by not making it an official exclusion, the practice of 'unofficial exclusions' is unlawful, even if you agree to it.
With an unofficial exclusion, the child potentially misses out on their education and you have no right to make representations to the school governors. It is therefore important to check the official status of the exclusion if you have not received a formal letter from the school by the end of the first day of the exclusion.
What happens if a child is excluded from school
ACE Education School exclusion
Coram Children's Legal Centre School exclusions
Statutory guidance for maintained schools, academies and pupil referral units on the exclusion of pupils