(Not directly answering the question asked, because sibling comments already did.) FWIW, I've heard and used it in FAANG for well over a decade. Usually I see

(Not directly answering the question asked, because sibling comments already did.) FWIW, I've heard and used it in FAANG for well over a decade. Usually I see HN comments using "IC" followed by someone asking what "IC" stands for. Makes a change to see someone asking for an expansion of the expansion :)