Unlike other messages, the EAN is not the alert itself, but rather a notice that the activation is beginning.[2] After the End of Message (EOM) tones are sent, normal programming does not resume. Instead, most stations will broadcast emergency information in a specific priority order. Messages from the President are always broadcast first. Next comes local messages, statewide and regional messages, and finally national messages not originating from the President (some documents refer to these as "messages from the National Information Center (or NIC)". While there is a SAME code for this type of message (NIC), there exists no FCC definition of the National Information Center)[3] . When an EAN is initially received, and during any time a new message is not available, an FCC mandated standby script is to be used (and repeated).[4] Other stations, which hold special permission from the FCC, will sign off until the end of the EAN.[5] Normal programming cannot resume until the transmission of an Emergency Action Termination message (SAME code: EAT)

[link to en.wikipedia.org]