Uniden XDECT 8355 Series Owner's Manual page 22

The table shows the possible status icons and what they mean. Since the
icons appear based on what the phone is doing, you won't see all the icons
at the same time.
Icon
1 2 3 4
[Aa] - [aA]
22
What it means
The signal from the base is 1) weak through 4) strong.
The ringer is turned off and will not ring for new calls.
Answer Machine ON/OFF status.
The handset is using ECO (power save) mode.
The speakerphone is on.
You have a voice message waiting.
T-coil mode is on (see page 24).
Privacy Mode is on: no other handset can join the call.
The battery levels;
Level 3 (Full)
Level 2
Level 1
Level 0 (Empty)
Bluetooth device number linked to the XDECT 8355.
Home phone line.
Enter 1) capital or 2) lower case letter (see page 26).
Appears when you are entering text.