The "Scan a code" alternative is useful for even faster adding of Guardians. It can be used when Vault12 Guard is already installed on both devices. In this case, the Guardian device's Vault12 Guard displays a QR code, and the Vault owner can scan it with their main device's Vault12 Guard. This QR-code-scanning process can be performed on “air-gapped” devices without being connected to a network, which is a slightly more secure channel of communication. However, this setup type requires slightly more effort, so is not recommended for first-time onboarding.