IP Office Basic Edition - Phone Based Admin:
The following settings affect system operation. These functions should typically only be performed when a system is first installed:
This setting is used to switch the system between key system mode and PBX system mode.
Set whether the system should use 2-digit or 3-digit extension numbering.
Set the locale (country) that the system is installed in. This value adjusts a range of hidden trunks settings and the default system language.
Set the default language for all extensions. The display language for individual extensions can be changed.