AT&T AT3111-2 - Manual (Page 21)

Telephone operation
17
Caller ID log
While on a call, you can press CID to review the
caller ID log. To dial the displayed number, press
MENU/
SELECT. To clear the entry from the display,
press and hold OFF
/CLEAR
.
NOTE: While reviewing the call log on a call, storing the
caller ID number in the directory is not allowed. For more
details about the call log, see page 27.
Options while on calls