DIFF Subgroup
G02B 27/0101 Full Title
Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 > Head-up displays
Of 15 combined children, 0 exist in both systems.
15 codes are CPC-only extensions.
Note: 14 CPC extensions are marked as secondary classification only.