The yellow background in any column indicates that the item is not confirmed. In the Station Name column, it means that we are unsure whether or not the station has the -FM suffix associated with the Station Name display. In the Emergency Alerts column, it means we are unsure whether the station has the Emergency Alert feature.
Info obtained from http://fmradiodx.wordpress.com/. The site's operator does not include HD subchannels or emergency alerts in their logs, and information may not be up to date. If HD subchannel/EA information is confirmed, the highlight will be removed.
Station has the emergency alert (EA) feature enabled. SPARC receivers and the Sangean HDR-18 display a triangle, while others Sangean receivers such as the HDR-14, HDR-15, and HDR-16 display an "a". Some brands may display a different symbol while others including the Sony XDR-F1HD and many car radios don't support the feature at all.
Song and artist information is displayed when an HD signal is locked. Many of these stations with Song/Artist Info also have Artist Experience (album cover display), although not all of them do.
Station displays traffic and weather information on supported receivers, mainly car receivers, although a software to that supports this feature also exists. This feature is only implemented on stations owned by iHeartMedia.