AT&T BL102-0S User Manual page 18

Registration and deregistration
Adding and registering handsets
If registration fails, the screen shows
manual
alternately. Please start again from Step 1.
Notes:
You cannot register a handset if any other system handset is in use.
f
You can only register one handset to the telephone base at a time.
f
To register HS... and ... see
14