The New Age Wizarding World of J.K. Rowling discussion

The Accidental Magic Reversal Squad is a squad of wizards whose job it is to reverse "accidental magic." These accidents are normally caused by young witches and wizards who have not learned to control their magic. They may also be caused by older wizards out of control, or severe, unintentional effects of charms or spells, such as splinching (in Apparation when a wizard or witch is split with one part remaining at the point of origin, and the rest of the wizard at the destination). For instance, the Accidental Magic Reversal Squad was sent out in the Harry Potter and the Prisoner of Azkaban book when Harry Potter inflated his Aunt Marge; they "deflated" her and erased her memory (the memory modification done by Obliviators).