what can be used as proof of identity
Identity document Since February 1, 2008, U.S. citizens may apply for passport cards, in addition to the usual passport books. Although their main purpose is for land and sea travel within North America, the passport card may also be accepted by federal authorities (such as for domestic air travel or entering federal buildings), which may make it an attractive option for people residing where state driver's licenses and I.D. cards are not REAL ID-compliant, should those requirements go into effect. TSA regulations list the passport card as an acceptable identity document at airport security checkpoints.[97]