Albus Dumbledore's unidentified charm on the Mirror of Erised

This charm was placed on the Mirror of Erised by Albus Dumbledore during the 1991-1992 Hogwarts School year to protect the Philosopher's Stone. The charm bewitched the Mirror to hold the Philosopher's Stone, where the only one who could retrieve it from the Mirror would be one who wanted to find the Stone but not use it or have it used.