I couldn't find anything in the manuals that I have. It seems that it represents your audio source with an icon. Anything that is broadcast over an antenna has an antenna displayed; XM, FM, AM. The other sources may or may not have icons. USB has a folder, CD has a CD.On the Nav screen (most views) between the Radio source and the radio channel?
Welcome to the Forum! Glad to see you made your first post.I believe that is for your HD FM stations icon.