Patent classifications
G
PHYSICS
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G07
CHECKING-DEVICES
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G07C
TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE
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9/00
Individual registration on entry or exit
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G07C9/20
involving the use of a pass
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G07C9/21
having a variable access code
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