Canon EOS Rebel T6i Basic Instruction Manual page 177

The nickname can be changed later from the [General sett.] screen.
Enter a nickname.
3
For instructions on entering

characters, see "Virtual Keyboard
Operation" on the next page.
Enter any characters between 1 to 14

characters in length.
Exit the setting.
4
When you are finished, press the

<M> button.
Select [OK] on the confirmation

dialog and press <0> to return to
the menu screen.
Registering a Nickname
W-15