Brother MFC-5860CN - Manual (Page 110)

100
25 Note that some telephones are not compatible with this unit and dialling errors may result if the
two devices are used together in other than quiet conditions. The Telecom Faults Service is
not to be called should such problems arise. In such cases, it is recommended that the prefix
and wanted number are dialled manually.
26 This equipment may not provide for the effective hand-over of a call to another device
connected to the same line.