AT&T SYSTEM 25 Manual page 73

Multiline
Leaving a Message While You Are Active on a Call
1
Press
2
Listen for confirmation tone and then hang up.
Leaving a Message Without Being Active on a Call
1
Lift the handset and listen for dial tone.
2
Press
3
Dial the PDC of the other person.
4 Listen for confirmation tone and then hang up.
Single-Line
Using the Leave Word Calling Feature
1
Lift the handset and listen for dial tone.
NOTE:
2
Dial
3
Dial the PDC of the person for whom you want to leave a message.
Listen for confirmation tone and then hang up.
4
2-60 Voice Terminal Features
[LEAVE WORD]
.
[LEAVE WORD].
You cannot activate Leave Word Calling on recall dial tone.