The only time I've ever seen anyone playing an AAC file is on an ipod. The only time I've ever seen someone create an AAC file is with iTunes. I know there are other compatible products (I read the wiki).

My point is that the FAQ entry is about iTunes and whoever's reading it should know that iTunes and AAC files are compatible mostly with Apple products and little else, and they should be encouraged to switch their iTunes to MP3 if they want the most compatibility with other players.