These document authenticity requirements focus on Tier 4 and Tier 3 documents. Tier 5, Tier 2, and Tier 1 documents are out of scope, but have been included as examples. The FIDO Secretariat SHOULD maintain a list of government documents and their respective tiers. Tier 2 and Tier 1 documents are out of scope because these documents do not contain sufficient security features to facilitate scaleable and effective fraud detection using only software and through a mobile device.