LG MM-535 Owner's Manual page 23

Your phone's display screen provides a wealth of information about your
phone's status and options. This list identifies the symbols you'll see on
your phone's display screen:
shows your current signal strength. (The more lines you
have, the stronger your signal.)
means your phone cannot find a signal.
tells you a call is in progress.
indicates Airplane mode is set.
indicates you are "roaming" off the Sprint Nationwide
PCS Network. (If you are roaming on an analog system, your
phone's display will show the roaming icon and an "Analog
Roam" text alert.)
indicates you have new text messages.
indicates you have voicemail messages. (Press and
hold
indicates you have new text and voice messages.
indicates your phone's location feature is on.
indicates your phone's location feature is off.
indicates your Sprint PCS Vision connection is active (data
is being transferred).
indicates Sprint PCS Vision connection is dormant (no data
is being sent or received).
indicates your phone is not currently able to access
Sprint PCS Vision service features.
indicates that the ringer is set at a level between Low-High.
indicates ringer volume is set to vibrate.
indicates ringer volume is set to High & Vib.
indicates that the ringer is turned off or Silence All mode is
set.
indicates that an alarm is set on your phone.
indicates your phone is operating in TTY mode.
to call your voicemail box.)