AT&T CL81211 - Manual (Page 8)

Getting started
3
Quick reference guide - telephone base
IN USE indicator
On when the handset is in use.
On when a handset is being registered.
Flashes when there is an incoming call or
when a handset is being deregistered.
Flashes when another telephone is in use
on the same line.
/HANDSET LOCATOR
Press to start the paging tone on all
handsets for 60 seconds. (page 23).