Yealink SIP-T42G - Manual (Page 73)

Customizing Your Phone
63
For more information on the valid value of the Account field, refer to Replace Rule
on page 59 .
4. Click Confirm to accept the change.
Note
You can block specific numbers (up 10) from being dialed on your phone. When you dial
a block out number on your phone, the dialing will fail and the LCD screen will prompt
"Forbidden Number".
To add a block out number via web user interface:
1. Click on Settings->Dial Plan->Block Out.
2. Enter the desired value in the BlockOut Number field.
The default values of minimum and maximum length are 1 and 15 respectively.
Area code is configurable via web user interface only.