Yealink SIP-T54S Administrator's Manual page 686

Administrator's Guide for SIP-T2 Series/T19(P) E2/T4 Series/T5 Series/CP860/CP920 IP Phones
To configure the shared line settings on the primary phone via web user interface:
Register the primary account (e.g., 4609).
1.
Click on Advanced, select Shared Call Appearance from the pull-down list of Shared
2.
Line.
Click Confirm to accept the change.
3.
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