Type DescriptionPDN Answers a call arriving at a Primary Directory Number (PDN)button simply by going off-hook. This works even when multiplecalls are received simultaneously.(® 13.1.7 PDN (Primary Directory Number)/SDN (SecondaryDirectory Number) Extension)Prime Line Answers a call arriving at a CO button (on which the "PrimeLine" is assigned) simply by going off-hook. This works evenwhen multiple calls are received simultaneously.Ringing Line (default) Answers the longest ringing call when multiple calls arrive atone’s own telephone simply by going off-hook.Conditions[Prime Line]• The priority of the incoming call is as follows:1. The call arriving at a button on which the "Prime Line" is assigned.2. The call arriving at the INTERCOM button.PC Programming Manual References6.1 [4-1-1] Wired Extension—Extension Settings—Option 4— Incoming Preferred Line6.10 [4-2-1] Portable Station—Extension Settings—Option 4— Incoming Preferred LineOperating Manual References3.1.2 Personal Programming10.1.3 Line Preference—OutgoingDescriptionThrough personal programming, a proprietary telephone (PT) user can select the preferred method of seizinga line (Preferred Line Assignment—Outgoing) that is used each time the user goes off-hook.Method DescriptionICM/PDN When an extension user goes off-hook, an extension line is selectedautomatically. If the extension is a PDN extension, the first availablePrimary Directory number (PDN) button is selected automatically.(® 13.1.7 PDN (Primary Directory Number)/SDN (Secondary DirectoryNumber) Extension)Idle Line When an extension user goes off-hook, an idle CO line is selectedautomatically from the assigned trunk groups.No Line When an extension user goes off-hook, no line is selected. In order tomake a call, the user must select the desired line manually.Document Version 2009-12 Feature Manual 17710.1.3 Line Preference—Outgoing