When X=7, the default value is 51 (Switch Account Up). 
When X=8, the default value is 52 (Switch Account Down). 
When X=9, the default value is 33 (Status). 
When X=10, the default value is 0 (NA). 
When X=11, 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-T23P/T23G/T21(P) E2 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 51 (Switch Account Up). 
When X=8, the default value is 52 (Switch Account Down). 
When X=9, the default value is 33 (Status). 
When X=10, the default value is 0 (NA). 
When X=14, the default value is 2 (Forward). 
Web User Interface: 
DSSKey->Line Key/Programable Key->Type 
Phone User Interface: 
Menu->Features->DSS Keys->Line Key X->Type 
To configure a DND key via web user interface: 
1.  Click on DSSKey->Line Key (Programable Key). 
2.  In the desired DSS key field, select DND from the pull-down list of Type. 
3.  (Optional.) Enter the string that will appear on the LCD screen in the Label field.