DIFF Subgroup
G09B 19/12 Clock-reading
Introduced: September 1968
Full Title
Full titles differ between systems:
IPC:
Teaching not covered by other main groups of this subclass > Clock-reading
CPC:
Teaching not covered by other main groups of this subclass (teaching or practice apparatus for gun-aiming or gun-laying F41G3/26) > Clock-reading
No child classifications to compare. This is a leaf node in both IPC and CPC.