DIFF Subgroup
H04M 15/20 Operator's time recording or indicating arrangements
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 > according to duration of call > Operator's time recording or indicating arrangements
CPC:
Arrangements for metering, time-control or time indication > Metering calls from calling party > Discriminative metering > according to duration of the call > Operator's time recording or indicating arrangements
No child classifications to compare. This is a leaf node in both IPC and CPC.