AT&T Classic Mail Voice Messaging System User Manual page 10

Figure 1A: Typical
Merlin telephones.
CLASSIC MAIL System Mailbox User Guide
You should also know how to perform these basic phone
operations:
Answer an outside call
Call another intercom
Transfer an outside call
Your phone should resemble one of the phones in Figure
1A. The number and types of buttons will vary depending
upon the model of phone system and the types of phone
sets you have. There should be voice mail labels on the
buttons similar to the one shown in Figure 1B for lines
that are assigned to the CLASSIC MAIL system.