Its in between the GPS and 4G symbol on top of my thunderbolt...it looks like this
o\r
What is that?
Page 39-
https://forums.androidcentral.com/e...derbolt/thunderbolt_manual.pdf&token=Kf-btqln
http://www.verizon.com/multimedia/mim/htc_thunderbolt/thunderbolt_manual.pdf
If it's not in here then it's from an app you downloaded.