A fixed plug key of the plug body is adapted to accommodate a socket key of the socket body, where the socket key may be disposed at multiple key positions.

The photodiode SFH203 (white transparent = P2) , has a flat keyed (flat side),

It further comprises at least a foolproof device (11, 12, 13).

The socket housing is further provided with a misplug-proof mechanism(1.1,1.2).

An electrically conductive second contact element is further arranged in the encoding lug.

The housing of the plug type connector has an encoding lug of electrically insulating material.

The keyway is mandatory for category HB4A and optional for category HB4.

P8 and P9 connectors have been replaced by a single tabbed connector.

The keyway is mandatory for category HB4A and optional for category HB4.

The keyway is mandatory for category HB3A and optional for category HB3.

The keyway is mandatory for category HB3A and optional for category HB3.

Each cable has a different coding for added security.

Glass bulb and supports shall not exceed the envelope and shall not interfere with insertion past the lamp key.

This can be viewed as a variation on the concept of slavery.

Glass bulb and supports shall not exceed the envelope and shall not interfere with insertion past the lamp key.