DIFF Subgroup
H04M 15/24 preventing metering of tax-free calls to certain lines, e.g. to fire or ambulance stations
Introduced: September 1968
Full Title
Full titles differ between systems:
IPC:
Arrangements for metering, time-control or time-indication > Metering calls from calling party > Discriminative metering > preventing metering of tax-free calls to certain lines, e.g. to fire or ambulance stations
CPC:
Arrangements for metering, time-control or time indication > Metering calls from calling party > Discriminative metering > preventing metering of tax-free calls to certain lines, e.g. to fire or ambulance stations
No child classifications to compare. This is a leaf node in both IPC and CPC.