Special group (finite group theory)

In group theory, a discipline within abstract algebra, a special group is a finite group of prime power order that is either elementary abelian itself or of class 2 with its derived group, its center, and its Frattini subgroup all equal and elementary abelian . A special group of order "p""n" that has class 2 and whose derived group has order "p" is called an extra special group.