Strong quasiautomorphism-invariant subgroup

Definition
A subgroup of a group is termed strong quasiautomorphism-invariant if it is invariant under all strong quasiautomorphisms of the group.

Stronger properties

 * Weaker than::Quasiautomorphism-invariant subgroup

Weaker properties

 * Stronger than::Characteristic subgroup
 * Stronger than::Normal subgroup