X ranges from 1 to 3 (for SIP-T40P/T40G/T23P/T23G) 
X ranges from 1 to 2 (for SIP-T21(P) E2) 
For ext keys: 
For SIP-T54S/T52S: 
X ranges from 1 to 3, Y ranges from 1 to 60. 
For SIP-T48G/T48S/T46G/T46S: 
X ranges from 1 to 6, Y ranges from 1 to 40. 
For SIP-T29G/T27P/T27G: 
X ranges from 1 to 6, Y ranges from 1 to 20, 22 to 40 (Ext key 21 cannot be configured). 
Note: It is not applicable to SIP-T19(P) E2/CP860/CP920 IP phones. 
Web User Interface: 
Dsskey->Line Key->Label 
Phone User Interface: 
Menu->Features->DSS Keys->Line Key X->Label 
Description: 
(Optional.) Configures the short label displayed on the LCD screen for line key. 
Note: It is only applicable to SIP-T52S IP phones. 
Web User Interface: 
Dsskey->Line Key->Short 
Phone User Interface: 
Menu->Features->DSS Keys->Line Key X->Short Label 
To configure an ACD key via web user interface: 
1.  Click on Dsskey->Line Key. 
2.  In the desired DSS key field, select ACD from the pull-down list of Type. 
3.  (Optional.) Enter the string that will appear on the LCD screen in the Label field.