So what happens on Facebook when you are discussing Negro's Head marked coins? Anyone young and brought up in today's PC world might acquire a ticket with NH in the future and not be able to ask the question and get an answer to what it means without being blocked.
People need to stop being offended on behalf of others, who, if they have half a brain will recognise that the offence is caused by context, and not just the use of any particular word(s).
Science is going to suffer too. Stefan's Law will have to be explained in some other way, so good luck with that one.