Programming System 25 Features; Considerations - AT&T System 25 User Manual

Programming System 25 Features

Although the cordless telephone has five (5) programmable
buttons, it must be administered as a 10-button multiline
telephone (set 303). This is because the cordless telephone
supports the message waiting feature, but the 5-button telephone
does not.

Considerations

Since the cordless telephone does not have a speakerphone
or display, and cannot be used as an attendant console,
features that depend on those requirements are not available
on the cordless phone.
If Send All Calls is programmed, select Single Ring
Reminder, because there is no visual indication when this
feature is activated.
The five programmable buttons on the cordless telephone
correspond to buttons 7 through 11 on a regular 10-button
telephone, as shown below.
Order of Appearance of Buttons
10