Yealink SIP-T2 SERIES Administrator's Manual page 357

Configuring Basic Features
Parameter Permitted Values Default
For SIP-T41P IP phones:
The default value of the line key 1-6 is 15, and the default value of the line key 7-15 is 0.
For SIP-T27P IP phones:
The default value of the line key 1-6 is 15, and the default value of the line key 7-21 is 0.
For SIP-T40P/T23P/T23G/T21(P) E2 IP phones:
The default value is 15.
For programable keys:
For SIP VP-T49G IP phones:
When X=1, the default value is 28 (History).
When X=2, the default value is 61 (Directory).
When X=3, the default value is 5 (DND).
When X=4, the default value is 30 (Menu).
When X=12, the default value is 0 (NA).
When X=13, the default value is 0 (NA).
When X=14, the default value is 2 (Forward).
For SIP-T48G/T46G IP phones:
When X=1, the default value is 28 (History).
When X=2, the default value is 61 (Directory).
When X=3, the default value is 5 (DND).
When X=4, the default value is 30 (Menu).
When X=5, the default value is 28 (History).
When X=6, the default value is 61 (Directory).
When X=7, the default value is 0 (NA).
When X=8, the default value is 0 (NA).
When X=9, the default value is 33 (Status).
When X=10, the default value is 0 (NA).
When X=12, the default value is 0 (NA).
When X=13, the default value is 0 (NA).
When X=14, the default value is 2 (Forward).
For SIP-T42G/T41P/T40P IP phones:
When X=1, the default value is 28 (History).
When X=2, the default value is 61 (Directory).
When X=3, the default value is 5 (DND).
When X=4, the default value is 30 (Menu).
When X=5, the default value is 28 (History).
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