By Geoff Mulvihill Most adults catching a flight in the U.S. starting May 7 will be required to present a passport or an upgraded state-issued identification card that meets federal REAL ID standards. The requirement is 20 years in the making, but with just weeks to go, not everyone is ready for it. Officials in at least one state have requested another extension before enforcement begins. Here’s what you need to know: What is REAL ID? It’s a driver’s license or other state-issued ID that meets security requirements mandated in a 2005 law passed in the aftermath of the Sept. 11, 2001, terrorist attacks. Obtaining an ID with the designation — indicated by a white star in a yellow circle in most states — means taking more documents to the…