What does Odysseus show the men to prove his identity?

Odysseus reveals his identity to the men by showing them the scar on his leg, which he received from a boar during a hunt in his youth. This distinctive scar serves as undeniable proof of his lineage and past, distinguishing him from any impostor. Additionally, he recounts specific details about his life and experiences that only he would know, further confirming his identity as the true king of Ithaca.