AT&T MERLIN LEGEND Release 2.0 Single-Line Telephone User Manual page 45

Features
Using Selective Callback for Busy
Extensions
1.
When you reach a busy extension, dial #55.
When you hear five short
2.
When the extension is free, the
3. When you hear priority ring (three rings), lift the
handset.
You hear three short beeps and the call is dialed automatically.
Using Selective Callback for Busy
Outside Lines
When you hear a fast busy signal while dialing an
1.
outside number, dial #55. (If, after dialing #55, you
hear a dial tone, finish dialing the number.)
2. When you hear five short beeps, hang up.
When the line is free, the Callback feature is activated.
When you hear priority ring (three rings), lift the
3.
handset.
You hear three short beeps, a dial tone, and the call is dialed
automatically.
5-6
Callback
beeps, hang
up.
Callback feature is activated.