The last job I had before where I am now, I assembled certain devices. We had several test fixtures and "dummy" fittings used for assembly. These are commonly called "slave" units, and to differentiate them from production hardware, they were clearly label with big letters, in black felt-pen, "SLAVE UNIT". One person noticed this and filed a complaint with HR claiming it was racially motivated/offensive, and I had to clean off the offending words and paint big red dots on them instead.
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