Question about display icon on LG220C

[whacker]

I have a friend with an LG220C on Net10, and he's seeing an icon on the external display he can't make sense of (I've seen it first-hand as well). It's right next to the battery level meter (right side), and looks kind of like a strip of photo or projector film, but it's not hi-res, of course, so that's just a guess as to what it even is intended to look like.

Anyone have a guess? There are a lot of these out there, so I bet someone knows...

[Lisme]

It's a pair of musical notes. It means the ringer is on.

[whacker]

Thanks! I'll be relaying that tip almost immediately.