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Change and cancel restrictions in general
By default, ongoing reservations can be changed or canceled (however, the reserve in advance settings might permit this in general or for specific items, see next part), but it is possible to disable this via the reservation module settings (see screenshot below). if this is disabled, it becomes possible to specify how many hours before the start the reservation can still be changed or cancelled (these settings will apply to every reservation):
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Change and cancel restrictions based on reserve in advance settings
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