Reminds me of the word used in old machinist and mechanic’s magazines for strange, unusual, or semi-secret techniques that aren’t well known. Plenty of these had a column called ‘Machinist’s Kinks’ or something of the sort. I have compilation of such columns on my bookshelf somewhere. Somehow the meaning of ‘Kink’ has shifted a bit, but the meaning here of ‘things kept secret’ remains
https://books.google.com/books/about/Everybody_s_Handbook_of_Machinist_s_Kink.html?id=4ehIAAAAMAAJ
