DIFF Subgroup
G09B 17/02 Line indicators or other guides or masks
Introduced: September 1968
Full Title
Full titles differ between systems:
IPC:
Teaching reading > Line indicators or other guides or masks
CPC:
Teaching reading (teaching lip-reading G09B21/00) > Line indicators or other guides or masks
No child classifications to compare. This is a leaf node in both IPC and CPC.