BT 1000 - Manual (Page 52)

48
Approval
Connection to the BT telephone network.
Synergy Handset is fully approved for connection to the
BT network provided it is used according to the
instructions in this guide. The telephone lines must
provide Multi-frequency (Touch Tone) dialling
capabilities.
It may be connected to Direct Exchange Lines and
switchboards (PBXs) with new plan (plug and socket)
arrangements.
Connecting to switchboards.
Synergy Handset is only approved for use with a
compatible switchboard including those which do not
provide secondary proceed indication. If you would like a
list of suitable switchboards, contact BT on 154. If you
do have a compatible switchboard, it cannot be
guaranteed that the telephone will operate correctly
under all possible conditions of connection. If you have
any difficulties, contact BT on 154.
Generally Synergy Handset can be connected to any
switchboard where a simple modern telephone can be
used to make and receive calls. Synergy Handset is
suitable for connection to switchboards which return
secondary proceed indication.