I've serviced computers where the ide cable key was hand-striped or with some other marking with a marker as opposed to the line (spoon's red wire) already keyed from factory, somewhere mid 90's. regular procedure at that shop i think at that time to mark any unkeyed cable found. not that i ever had to mark any single one, so even then they were really old ide cables.

Actually...i kind or remember a motherboard coming up in smoke from one of those when someone made a mistake. brand new first week technician i think.