Step 1: Understand what an AVL tree is. An AVL tree is a type of binary search tree that maintains balance to ensure efficient operations.
Step 2: Know the properties of AVL trees. They must have unique keys, meaning no two nodes can have the same value.
Step 3: Identify the question. It asks which property is NOT true for AVL trees.
Step 4: Recall that AVL trees do not allow duplicate values. This is a true property of AVL trees.
Step 5: Conclude that the statement 'AVL trees do not allow duplicate values; they maintain unique keys' is true, and thus the property that allows duplicates is NOT true for AVL trees.
