AT&T DLP73450 Complete User's Manual page 148

Appendix
Add and register handsets/headsets
If registration fails, the system will automatically try to register again. If
registration fails after the third try, Registration failed appears on the handset
screen. The handset shows To register HS... and ...see manual, and the
telephone base returns to idle mode. This may take up to five minutes to occur.
Please start again from Step 1.
Notes:
You cannot register a handset if any other system handset is in use.
f
If you try to register more than five handsets to the telephone base, the telephone base shows Registration slots
f
are full and sounds two beeps..
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